The difference between 38% of a number and 24% of the same number is ` 135.10. What is 40% of that number?
(a)370
(b)378
(c)386
(d)394
Answer
Answer (as printed): C
Explanation
Let the number be $x$. Then, $38 \%$ of $x-24 \%$ of $x=135.10$ $\Rightarrow \frac{38 x}{100}-\frac{24 x}{100}=135.10 \Rightarrow \frac{14 x}{100}=135.10$ $\Rightarrow x=\left(\frac{135.10 \times 100}{14}\right)=965$. $\therefore 40 \%$ of $965=\left(\frac{40}{100} \times 965\right)=386$.
Explanation as extracted from the printed page; notation may be imperfect.