Question

The last three digits in 10! are ______.

• A. 800
• B. 700
• C. 500
• D. 600

Answer 1

The correct option is A

800

Solution: In 10!, we multiply the numbers from 1 to 10. It includes 2, 5 and 10 which when multiplied gives 100. This means the last two digits will be 00, because it is a multiple of 100. We have to find the last digit when we multiply the remaining numbers. For this, we will consider only the last digit.

Last digit of(1 $\times$ 3 $\times$ 4) =2

Last digit of(6 $\times$ 7) =2

Last digit of(8 $\times$ 9) =2

Last digit of (1 $\times$ 3 $\times$ 4 $\times$ 6 $\times$ 7 $\times$ 8 $\times$ 9) = Last digit of(1 $\times$ 3 $\times$ 4) $\times$ Last digit of(6 $\times$ 7) $\times$ Last digit of(8 $\times$ 9)= 2 $\times$ 2 $\times$ 2 =8

The last three digits are 800