Question

Determine which digit will be at the unit’s place in the square of a number 999.

• A. 4
• B. 1
• C. 3
• D. 6

Answer 1

The correct option is B

1

As per the rule of square of a number, the unit digit for a square of number is determined by the product of the unit place digit of a given number whose square we have to find. So in the case of 999, unit place digit is 9. So the unit place digit in a square of 999 is, 9 $\times$ 9 = 81 i.e 1

So, ${999}^2$ has a digit 1 at unit place.