Question

A number consists of two digits whose sum is 5. If the unit's digit is multiplied by $\frac{9}{2}$, it will be equal to three times the ten's digit. Find the number.

• A. 41
• B. 23
• C. 14
• D. 32

Answer 1

The correct option is D

32

Let the units digit be $x$

Ten's digit = $5-x$

According to the given condition

$\Rightarrow \frac{9}{2}\times x=3\times (5-x)$

$\Rightarrow 9x=6(5-x)$

$\Rightarrow 9x=30-6x$

$\Rightarrow 15x=30$

$\Rightarrow x=2$

$\therefore$ The number is 32.