Question

Question 16

Write the correct answer from the given four options.

Which among ${43}^2$, ${67}^2$, ${52}^2$, ${59}^2$ would end with digit 1?

a) ${43}^2$
b) ${67}^2$
c) ${52}^2$
d) ${59}^2$

Answer 1

We know that, the unit's digit of the square of a natural number is the unit's digit of the square of the digit at unit's place of the given natural number.
$\therefore$ Unit's digit of ${43}^2=9$ $[\because 3^2=9]$
Unit's digit of ${67}^2=9$ [$\because$ unit's digit of $7^2$ is 9]
Unit's digit of ${52}^2=4$ $[\because 2^2=4]$
Unit's digit of ${59}^2=1$ [$\because$ unit's digit of $9^2$ is 1]
Clearly, the square of 59 end with digit 1.