Question

What is the largest integer $n$ such that $7^n$ divides $1000!$ ?

Answer 1

Answer:

The correct answer is

n = 3038

Step-by-step explanation:

Where we have;

We note that 1000! = An even number

Since Even × Even = even

Even × Odd = Even

Also, 7ⁿ is an Odd number since odd × odd = odd

Therefore 7ⁿ will divide 1000! with some fractions as follows;

1000! divided by 7ⁿ

When 7ⁿ = 1000!

log(7ⁿ) = log(1000!) = log(4.02×10²⁵⁶⁷)

n·log(7) = 2567.604

n = 2567.604/(log(7)) = 3038.23

Therefore, the largest integer n such that 7ⁿ divides 1000! = 3038

Which gives, 1000! ÷ 7³⁰³⁸ = 1.5733.