The visuals are a HUGE help, thank you for uploading this!! This is such a simple concept but for some reason my brain was melting trying to decipher it just from words on a slide.
In the problem at 5:00 shouldn't the answer be floor(1000/77) since the question asks the number of positive integers divisible by 7 AND 11 and not 7 OR 11?
I'm not sure which example you are referring to. However, unless the question specifically states that repeated digits are not allowed, you can assume that digits can be repeated.
The visuals are a HUGE help, thank you for uploading this!! This is such a simple concept but for some reason my brain was melting trying to decipher it just from words on a slide.
Thank you so much! This is probably the 5th video I've seen on the subject and by far the one the helped me the most!
It is indeed very well explained
You're very welcome!
this is the best video on this topic. started from the ground and progressively get harder, thank you for the help!
Glad it helped!
for example 10:55 , for B and C situations , we cant start with 0 because it would be 9 digits. So this solutions are wrong i think. Am ı wrong?
I think the question about the divisibility seems to be 7 or 11 instead of 7 and 11.
Had to pause the video there myself. I agree, should be 7 or 11 because Union is 'OR' and Intersection is 'AND'.
In the problem at 5:00 shouldn't the answer be floor(1000/77) since the question asks the number of positive integers divisible by 7 AND 11 and not 7 OR 11?
wondering that too
Legendary teacher
Best explanation
Very clear and helpful. thanks !
Thanks prof. It was really helpful!
Ma'am you didn't mention whether the digits have repetition or not?
I'm not sure which example you are referring to. However, unless the question specifically states that repeated digits are not allowed, you can assume that digits can be repeated.
why do we need the (-1)^n+1?
That alternates adding and subtracting.
thank u so much
Great
Nice
Woah...
time waste video!