Question

the sum of the digits of 2 digit number is 10. And the digit at unit place is 2/3rd of the digit at tens place. Find the number

Answer 1

Let the digit of unit place be y and the digit of tens place be x.
Then, number will be 10x + y.
According to the question,
$$\begin{gathered} x+y=10...\left(1\right) \\ \mathrm{and} \\ \frac{2}{3}x=y \\ 2x-3y=0...\left(2\right) \end{gathered}$$
Solving eq (1) and (2) we get,
x = 6 and y = 4
So the number is 10 × 6 + 4 = 64.