Question

Question 3
Find the values of the letters in the following and give reasons for the steps involved.
$1A$
$\underset{–}{\times A}$
$\underset{–}{9A}$

Answer 1

On putting A = 1, 2, 3, 4, 5, 6, 7 and so on, we found that the
unit digit of square is same as that of number for A = 6 only.
$A\times A=6\times 6=36$ in which ones place is 6.
$\therefore A=6$