Grade 8/9 Ratio Problems
ฝัง
- เผยแพร่เมื่อ 6 มิ.ย. 2018
- In this video I go through 7 difficult ratio problems with a few different strategies. Ratios is often a topic where people struggle, perhaps because it's hard to pin down a particular method that works best.
questions from the video (pdf) - bit.ly/34DACWc
Also thanks for 4000 subs! I can't believe it!
correction: In 24:19 15/33 can be further simplified to get 5/11.
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I seriously hate ratios
tmrw is our exam lol
Me too
Same
Hello 333 you have your mocks soon ?
REAL
It's impressive that a video about math has no dislikes, I thought kids loathed math (and many other subjects) with their hearts 🤣
I have been surprised since I started this channel at how positive it has been!
Maths Explained Math haters are not going to search up math on youtube are they?
@@ubaidshah1910 aha literally
could be forced :?
Thanks for your great videos. On the last question I just used the values 7x and x for natives to tourists and only had one variable. Do keep on with your videos please because they are invaluable!
Nice 👍 you are right, I didn’t use the simplest methods
I watched this video and it was so helpful, in fact one of the questions you covered was in my exam! Thankyou
You have no idea how helpful this was. Thank you so much!!
Omg this is amazing! Ratios are the bane of my nightmares, thank you very much! This will be good some good revision over the weekend for Paper for any ratios ^^
I feel like I messed up in Paper 2 in my graphs; in the quadratic graph, my lines were a bit wobbly which might have affected my solutions for part c. Also the question circle graph, I may have somehow messed it up by not reading the values correctly from the graph. I definitely messed up the surface area question, I forgot to add the other two sides of the 1/4 sphere haha, rip. I probably lost 3 marks there.
I hope don't get below 80% in this paper, or I'll probably not get a 9. I need to prepare well for paper 3.
Siam Sama how did you do
So, i answered your Bill and Donna question, (the second one in the video) however i used a different method instead of algebra,
I did:
A:B = 2:5 , C:D = 3:1 , I balance out the total amount of parts, e.g. 28
So now I have A:B = 8:20 , C:D = 21:7, Then since C and D shared twice the amount of money i halved A:B as C:D shared double to get 4:10:21:7
You are correct
Ohh yeah thanks i prefer tjis way a lot more
tysm
i did the same thing because algebra doesn’t work for me haha
howd you balance out it i dont get it@@imnotlelo
this guy is so smart if only this shit was as easy as this guy does it tho
Excellent video, mate! Thanks:))
Thanks for this, really needed this
I always get called stupid for not knowing how to do ratios by set 3 and I’m in set 1. But what they don’t know is they do the baby ratios whereas we are doing stuff like this which my grade 6 brain cannot do
It actually kind of hurts, your shamed when you don’t know how to get it quick. It makes me doubt myself that all the other students get it quick.🙁
im literally crying thank u so muchh
Please do Unofficial mark scheme for paper 2. I think the paper was fairly easy and wasn’t too tricky hopefully, we all do well. Please do a mark scheme I was waiting all day as well today please !!!
thank you, this was good revision for my upcoming ratio exam
lol same
Ugh Fortnite kid
Are you going to do a paper 2 higher 2018 edexcel review I want to kinda know what I got
Bob John He's not allowed to, edexcel will remove it
@@ipodzonly123 how? I see loads of vids online kn it amd hes posting it after the exam anyways?
I did the second ratio question with Anna, Bill, Carl and Donna differently. A:B is 2:5 = 7 parts. C:D is 3:1 = 4 parts. Find the lowest common multiple of 7 and 4 parts which is 28. A:B have to be multiplied by 4 whilst C:D have to be multiplied by 7. However as C:D has twice as much money it needs to be doubled. This gives you 8:20:42:14. This simplifies to 7:10:21:7.
Should be 4:10:21:7. Also, in the video, the poster did 3/4 x 2x incorrectly --> should be 3/2 x
You deserve a lot more subscribers
3:22 question 11 there is a simpler way to solve this *without unnecessary algebra*.
The common denominator of both ratios would be 28. Multiply the first ratio A:B by 4 to make 8 : 20, then multiply the second ration C : D by 7 to make 21 : 7, and double C:D to show they share double the amount, you get
A:B:C:D = 8:20:42:14
this simplifies to
A:B:C:D = 4:10:21:7
btw the question w the sweets fully simplifies to 5/11
Can you please give us an unofficial mark schemes like you did last time.
These questions are explained well on the Gsce Revision guide 9-1 Higher maths .
thanks i needed to practice these
thank you so much
this really helped
Paper 2 was great, can ppl tell me what they got for the quarter sphere? I got 452 for the surface area. Thanks for the vids by the way
you forgot to also add the area of circles in the shape because you just calculated the curved surface area. I did the same, probs still got 3 marks
Ammar Ourtashi yh i got that
ali xone Thanks, was wondering what I did wrong
i got that too if i remember correctly
In 24:19 15/33 can be further simplified to get 5/11.
If i had a question like a choir has 2/3 as many female as male members. Write the number of female to male members how would I do that.
Try to think about what “2/3 as many female as male members” means. That means for every 3 male members, there are 2 female members. Or to put it another way, if there were 9 male members, there would be 6 female members.
So the ratio is 2:3.
thanks for saving my life :)
23:47 Was that the sound of a plate? Presumably one with sweets? :D
How did you get to 2:5 : 21/2 :7/2 ? Please reply
Abbey and the two triangles question. I used the area of a triangle formula and got: Triangle A: 10=0.5bh therefore h=20/b. Triangle B: 45=0.5x3bx(h+1) therefore h+1=30/b. The ratio of h:h+1 is therefore 20/b:30/b. Simplify gives 2:3. I didn't think it was necessary to find the value of b as the question is asking for the ratio of the heights.
Thanks. I knew there was a shorter method!
For the third one I set up an equation as the total amounts of the paint would be equal before and after, after adding the blue paint as no white paint is added: 7(15)/5 + x=5(15+x)/4 and solved for x; did I just make it too complicated or did I find the answer using an incorrect method, as I still got 9?
Yes that works. So what your saying is that one part of the ratio will still be the same (3 litres), so what you add on (x) can be found by making the proportion of blue paint before and after equal.
Oh awesome! Ratios are my major weak point, but by using algebra it makes it a bit easier for me, still sometimes I feel like I'm doing it wrong :/
I prefer to solve them algebraically too, however there is often a simpler method. Don't worry, if you use algebra, you can rarely go wrong, but just be aware it is not always the fastest way.
24:20 it's 5:11
You can simplify 15/33 by 3
for the second question in a different, simpler way but got the same answer:
2:5 = 7 parts . 3:1 = 4 parts
want them the same so 28 parts each and multiply up
8:20 . 21:7
but first one is half the second
4:10 . 21:7
so 4:10:21:7
He made that more long-winded than it needed to be
Wdym first one is half the second?
this video is so powerful.
his mind>>
that was brillian thank you
Great video - students that can answer all these questions won't have any problems in an exam.
Minor point 6:19 should be 2x. and the ratio will be 4 : 10 : 21 : 7
on the third question, can someone explain how he got 9 litres?
for the candy question, does it not simplify to 5/11?
Yes. I'm guessing I didn't write that 😩
this helped me alot
Which exam board are these papers form . Great video
Most likely to come in most of exam boards
Where do you get questions like these
These were sent in by subscribers. Not sure where they are originally from sorry
can you do the lower quartile question
Ming Ree It was 10
I got 6 but probs got it wrong by doing: (n+1)/2 = (23+1)/2 = 12 = median lq : =12/2 = 6
For the second question you can simply say Anna + BILL = 70 use that to work out their values and then x2 and work out Carl and Donna's value's . Then Put them back together and you get that final answer.
This method is soooo much easier than the method in this video to the point that I could just do it in my head.
Nice, thank you for sharing. I tend to take an algebraic approach to these and it is not always the best way.
How do all of them write so neat on computer. Someone plz answer this question
I don't know about anyone else but I use a drawing tablet like this one: www.wacom.com
You can get them cheap second hand (about $20)
Maths explained, I want more videos on gcse maths papers than a level maths paper. There are so many videos on a level but only few for gcse
Paper 2 went well but everyone found it well so I’m scared the grade boundaries are gonna be really high this year
U97gaming ikr i wanted a 9 but im getting an 8 paper 3 should turn it around
9Firmino so it couldnt decrease slightly
There is a shortcut for the question at 14:15 .. he explains it very well but that's what makes it confusing sometimes lol
Thank you soo mucj
This probably sounds dumb but why aren’t you multiplying the denominators when cross multiplying?
It’s Ashton if you’re talking about the second question it’s because your multiplying out the 2s to get rid of them
Minor error but at 24:16 15/33 can be further simplified to 5/11.
👍 thanks
nice teaching skills
The question with 4 ratios A:B:C:D about 6 mins in, i dont understand at all.
I reckon I’m going to get 150-165 marks, is that just a 7?
Ammar Ourtashi I thought the same Ammar.
It's hard for me because we haven't studied it at least once we might have when I was going on a math competition or something else
How was ur maths competition?
It's kind of annoying that there hasn't been any harder topic so far. Such as sin, cos rule, harder circle theorems or geometric question, geometric or quadratic sequences, harder vectors or probability questions atc... (what I was revising the most)
I literally was struggling with these easier questions, since it was so hard to belive that you only need to use "basic math" in order to find the soultion, it was a bit confusing.
Anyway good luck for everyone:)))
It is complex because it combines all of the simple ones. Only people who think logically can do these questions and I suck at these but the more you practice the more you’ll get it
I love the question at 9:12. Admittedly, it took me 2 attempts and 10 minutes but I got it in the end. Given the amount of extra time I am having at the end of the maths exams so far, I'm not too worried.
Hi sir. I lost a maximum of 10 marks in paper 1 and a maximum of 10 marks in paper 2. What do you think I need to get in paper 3 to get a level 9?
So your on about 140 marks. I would say 60 to be safe
Well done btw!
Great! I think 60/80 is very doable. Thanks :)
wow how do you revise
I revised by doing every past paper I could. If you do that, you end up institutionally knowing how to answer each type of question before you even read it. It is a bit late now if you are taking the exams this year but if you do past papers before the last paper your grade WILL go up a lot. Good luck!
second to last question is 5/11 as you can simplify further by dividing by 3
I deserve a grade 0 😭
Is it possible that these types of ratio can come up on paper 3??
Great videos. Thank you
Just one comment. You pronounce h with an A followed by ch sound No offence intended, but just letting you know. Thanks
It’s ok 😄
With the last question you can just have 7X:X to make it alot easier tho
Hi Sir
I am a teacher. In the corona days I find myself needing to teach my students on line and to record lessons and send to them.
could you please make a video on how to do that and what is needed to do that in terms of software and hard wardware etc.
much appreciated and many thanks.
how I make videos: bit.ly/2QA2WUo (I know it is not a video but I hope still shows clearly how I do it)
@@maths.explained
Many thanks for your quick reply. I will definitely explore that.
keep up your good work it is very helpful.
shouldnt carl have 3/4 times 2 equals 6/4
yes and 6/4 simplifies to 3/2, I correct myself at 6:50
Ah ok thanks
This is good no problem
My exam is next week and if I fail I’m goin set 2
13:40 so much pain
cant 3:15 be more simplified ???
The triangle question is incorrect all the work is right but you simplified it incorrectly so that the base should actually be 20 not 10 which overall makes the ratio 1:3 please correct me if I’m wrong
I believe all the simplifying is correct.
0.43 for the last one
I got 0.4
i got 0.4 mate
voidz It's 0.43
Nikolia Da Vinci i got 0.43 but represented it in an error interval😞
Manor Gaming still 4 marks. Don’t worry.
three man shared 480 in the ratio 7:8:9 find the greatest share
king Joe 180
Am I the only who got 8:5 for the ratio question
i got that but it was supposed to be 3:5 i dont know how but i must have mistypes on my calculator, im gutted because i got the 1: 1.6 reocurring part right :(
I did q2 so simply not that method
You don’t really need much working out. I did it that way because a few students were struggling to understand why the second ratio was divided by 2.
16 18 this is the one i was looking for thank u sooooooooooooo much
I don't get 7:11
Same like wtf ??? 🤔😩
@@trishna9648 im a bit late but he was multiplying everything by 7.
I worked out Abbey's triangles question without seeing that they gave us the area for triangle B. It made it quicker.
(h×b)/2 =2a
(3b(h+1))/2 =9a
hb=4a
3b(h+1)=18a b(h+1)=6a
hb= 2/3 ×b (h+1)
h=2/3(h+1)
2/3 : 1 = 2:3
Yes you don’t actually need the areas. Feel free to share you method, others will want to see it
Hello, could you send me your email, so i can email you regarding a topic i struggle with and you giving me advice/links or a video you can make.
Mathsexplained2@gmail.com
Easy questions
19:49
maaaud
i only got the first one right :(
24:20 Nope i checked it was a 6 mark question
im 80:20 on whether i understand or not
im sorry
a: b=2:3
b:c=5:6
Show that a:c=5:9
teaching too fast cant understand what you say
Sir their is a mistake on 5:32
I corrected myself about 30 seconds later in the video
How is this even a year nine subject seriously it is the most difficult and confusing
the grade 8/9 refers to the level of difficulty. Grade 9 is the highest grade possible on GCSE exams
Oh sorry fo miss understanding
@@dariocaputo7158 ikr it’s so confusing