Question

second square of five-digit number made of numbers one

Answer 1

Answer:

90625

Step-by-step explanation:

a five digit number, so that its square has its last five digits equal to the number

Let say number = n

then n² - n  would be divisible by 100000

as last 5 digit of n² are same as n

=> n(n-1)  divisible by 100000

=> n(n-1) divisible by  10⁵

=> n(n-1) divisible by 2⁵ * 5⁵

on solving we get number = 90625

90625² = 8212890625