Question

The sum of the digits of a two-digit number is 6. If the digit in tens place is twice the digit in the units place, then find the number.

Answer 1

Let the digit in the units place be $x$.
According to the question, the digit in the tens place is $2x$. Sum of digits is 6.

$\therefore 2x+x=6$
$\Rightarrow 3x=6$
$\Rightarrow x=2$

Hence, the units digit is 2 and the tens digit is $2\times 2=4$.
Thus, the number is 42.