Question

If $B\times B=AB$, then either $A=2,B=5$ or $A=\_\_\_\_\_,B=\_\_\_\_\_\_\_\_\_.$

• A. $3$
• B. $6$

Answer 1

Explanation for the correct answer

Given that $B\times B=AB$, and either $A=2,B=5$

Here $B\times B$ is a two digit number, whose unit digit is $B$.

Therefore,

$B\in (0-9)$

Only $5$ and $6$ are the number whose product with itself is a two digit number with unit digit itself

So, $B=5$ or $6$

If $B=5$ then

$5\times 5=25$

$\therefore$$A=2$

If $B=6$ then

$6\times 6=36$

$\therefore$ $A=3$

Hence , $A=3$ and $B=6$.