Subject: General Aptitude · Chapter: Problems on Numbers · Exam: · Marks: · Difficulty:
One-fifth of a number is equal to $\frac{5}{8}$ of another number. If 35 is added to the first number, it becomes four times of the second number. The second number is
(a)25
(b)40
(c)70
(d)125
Answer
Answer (as printed): B
Explanation
Let the numbers be $x$ and $y$. Then, $\frac{1}{5} x=\frac{5}{8} y \Leftrightarrow y=\frac{8}{25} x$. Now, $x+35=4 y \Leftrightarrow x+35=\frac{32}{25} x$ $$\Leftrightarrow \frac{7}{25} x=35 \Leftrightarrow x=\left(\frac{35 \times 25}{7}\right)=125 .$$ $\therefore \quad$ Second number $=y=\frac{8}{25} x=\left(\frac{8}{25} \times 125\right)=40$.
Explanation as extracted from the printed page; notation may be imperfect.