Can I ask that How we can use these formulas without using a calculators? Are there any math recipe for it?

Hey! Do you mind sharing an example of past IMAT paper where you needed to use them? It seems not part of the syllabus

Oh, the question is just calculate C9,3.

And in the picture, I have shown before is a formula used to calculate.

Are you sure it’s from past IMAT? I am pretty sure it’s not on the IMAT, or maybe we have a different conversion in Europe.

@Juliette might know in this case.

hi

@AriHoresh

i agree this is a different notation of combination problems

C(9,3) means “how many groups of 3 can we make from a sample of 9”

this is an easier formula to use:

C=n!/(r!(n-r)!

with n=total number of samples=9, and r=samples in the grouping=3

C=9!/3!(9-3)!

=9!/3!6!

=(7 * 8 * 9)/(1 * 2 * 3)

=84

explanation video: https://www.youtube.com/watch?v=p8vIcmr_Pqo=