Question

Evaluate 7C3
OA) 25
O B) 45
OC) 35
OD) 20

Answer 1

C) 35

Explanation:

`^7C_3 \\ = (7!)/(3!(7 - 3)!) \\= (7!)/(3! \: 4!) \\ = (7 * 6 * 5 * 4!)/(3 * 2 * 1 * 4!) \\ = (7 * 6 * 5 * 4!)/(3 * 2 * 1 * 4!) \\ = 35 \\ \huge \red{ \boxed{ \therefore \: ^7C_3 = 35}}`

Answer 2

C=35

Explanation:

⁷C₃

These is combination

using the rule it states that

ⁿCₐ= n!/(n-a)!a!

so therefore ⁷C₃= 7!/(7-3)!3! = 7!/4!3!=7x6x5x4x3x2x1/{(4x3x2x1)x(3x2x1)}

4x3x2x1 cancels itself as it appears up and down

7x6x5/6

6 cancels each itself as it appears up and down

7x5 = 35