Question

What is 7P4 A: 28 B: 35 C: 210 D: 840

Answer 1

Answer:

D

Step-by-step explanation:

using the definition of n$P_{r}$ = $\frac{n!}{(n-r)!}$

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

here n = 7 and r = 4, hence

7$P_{4}$

= $\frac{7!}{3!}$

= $\frac{7(6)(5)(4)(3)(2)(1)}{3(2)(1)}$ ← cancel 3 × 2 × 1 leaving

7$P_{4}$ = 7 × 6 × 5 × 4 = 840 → D

Answer 2

Answer:

C. 210

Step-by-step explanation:

Evaluate the expression. Choose the best answer.

A. 840

B. 120

-C. 210-

D. 2,520