Subject: General Aptitude · Chapter: Problems on Numbers · Exam: 2004 · Marks: · Difficulty:
The ratio between a two-digit number and the sum of the digits of that number is 4 : 1. If the digit in the unit's place is 3 more than the digit in the ten's place, then the number is
(a)24
(b)36
(c)63
(d)96
Answer
Answer (as printed): B
Explanation
Let the ten's digit be $x$. Then, unit's digit $=x+3$. Number $=10 x+(x+3)=11 x+3$. Sum of digits $=x+(x+3)=2 x+3$. $$\begin{aligned} \therefore \quad \frac{11 x+3}{2 x+3}=\frac{4}{1} & \Leftrightarrow 11 x+3=8 x+12 \\ & \Leftrightarrow 3 x=9 \Leftrightarrow x=3 \end{aligned}$$ Hence, required number $=11 x+3=11 \times 3+3=36$.
Explanation as extracted from the printed page; notation may be imperfect.