PS 14

[magical cook]

C(m,n) = m! / [(m-n)! n!] for nonnegative integers m and n, m ³ n. If C(5,3) = C(5,x) and x ¹
3, what is the value of x?
A. 0
B. 1
C. 2
D. 4
E. 5

Hi, somehow I got it wrong. hope someone could help...

[gabriel]

C(m,n) = m! / [(m-n)! n!] for nonnegative integers m and n, m ³ n. If C(5,3) = C(5,x) and x ¹
3, what is the value of x?
A. 0
B. 1
C. 2
D. 4
E. 5

Hi, somehow I got it wrong. hope someone could help...

According to the given information C(5,3)= 5!/(3!*2!) ... and C(5,x) = 5!/((5-x)!*x!) .. now if you compare the 2 denominators you will see that only x = 2 will give the values 3 and 2 (which is what we want if they have to be equal) in the denominator, so the answer is C, that is x = 2..

Regards

[magical cook]

Hi gabriel - got it - thanks!