Combinations problem : Magoosh

Hi Everyone!

I'm new to the club. If anyone can assist me with this problem, I would be very appreciated

The topic is about Combination. Why is that 10C4 = 10C6? I understand that if we select a group of r from a pool event, we automatically create another group of (n-r) folks who were left behind. So every group of 4 corresponds to a group of 6. But if we calculate it, 10C4 = 10*9*8*7/4*3*2*1. On the other hand, 10C6 = 10*9*8*7/6*5*4*3*2*1. How is this equal to 10C4? Can someone please clarify?

Thank you

Angiee1112 wrote:Hi Everyone!

I'm new to the club. If anyone can assist me with this problem, I would be very appreciated

The topic is about Combination. Why is that 10C4 = 10C6? I understand that if we select a group of r from a pool event, we automatically create another group of (n-r) folks who were left behind. So every group of 4 corresponds to a group of 6. But if we calculate it, 10C4 = 10*9*8*7/4*3*2*1. On the other hand, 10C6 = 10*9*8*7/6*5*4*3*2*1. How is this equal to 10C4? Can someone please clarify?

Thank you

Angiee1112 wrote:Hi Everyone!

I'm new to the club. If anyone can assist me with this problem, I would be very appreciated

The topic is about Combination. Why is that 10C4 = 10C6? I understand that if we select a group of r from a pool event, we automatically create another group of (n-r) folks who were left behind. So every group of 4 corresponds to a group of 6. But if we calculate it, 10C4 = 10*9*8*7/4*3*2*1. On the other hand, 10C6 = 10*9*8*7/6*5*4*3*2*1. How is this equal to 10C4? Can someone please clarify?

Thank you

10C4 is not equal to 10*9*8*7/4*3*2*1.

10C4 = (10*9*8*7)/[(4*3*2*1)(6*5*4*3*2*1)]

Posted from my mobile device

Hi,

I think you are repeating the same post.

https://gmatclub.com/forum/combinations-problem-349598.html