What is 7p4 a: 28 b: 35 c: 210 d: 840

The expression is an illustration of permutation.

The result of   is (d) 840

The expression is given as:

The formula of permutation is:

So, we have:

Expand

Hence, the result of   is (d) 840

Read more about permutation at:

link

D

Step-by-step explanation:

using the definition of n =

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

here n = 7 and r = 4, hence

7

=

= ← cancel 3 × 2 × 1 leaving

7 = 7 × 6 × 5 × 4 = 840 → D

b

step-by-step explanation:

u take $75 minus $60.the anwer/original($75)multiply by 100