Question

This is all the question gave me 6 C 2 = _______ a0

Answer 1

Answer:

15

Step-by-step explanation:

Using the definition of n$C_{r}$

n$C_{r}$ = $\frac{n!}{r!(n-r)!}$

where n! = n(n - 1)(n - 2) × 3 × 2 × 1

Hence

6$C_{2}$

= $\frac{6!}{2!(4!)}$

= $\frac{6(5)(4)(3)(2)(1)}{2(1)4(3)(2)(1)}$

Cancel 4(3)(2)(1) on numerator/ denominator, leaving

= $\frac{6(5)}{2(1)}$ = $\frac{30}{2}$ = 15