A student was asked to divide the half of a certain number by 6 and the other half by 4 and then to add the… · ABC26GN1665
Subject: General Aptitude · Chapter: Problems on Numbers
A student was asked to divide the half of a certain number by 6 and the other half by 4 and then to add the two quantities so obtained. Instead of doing so the student divided the number by 5 and the result fell short by 4. The given number was (P.C.S., 2009)
(a)240
(b)288
(c)384
(d)480
Answer
No answer key was printed for this question.
Explanation
Let the number be $x$. Then, $\left[\frac{(x/2)}{6}+\frac{(x/2)}{4}\right]-\frac{x}{5}=4 \Leftrightarrow \frac{x}{12}+\frac{x}{8}-\frac{x}{5}=4 \Leftrightarrow \frac{10x+15x-24x}{120}=4 \Leftrightarrow x=4\times120=480$.
Explanation as extracted from the printed page; notation may be imperfect.