Question

Solve the expression:
$?\% 400 = 60$
(A) $6$
(B) $12$
(C) $15$
(D) $20$

Answer 1

Hint: replace the question mark with $x$ and then use the formula of percentage.

Complete Step by Step solution:
Let $x$ be the number. And our output value is 60.
Then, from the question, we can write
$x\% \times 400 = 60$
$ \Rightarrow \dfrac{x}{{100}} \times 400 = 60$
By simplifying the above equation, we can write
$\dfrac{x}{{100}} = \dfrac{{60}}{{400}}$
$ \Rightarrow x = \dfrac{{60}}{4}$
$ \Rightarrow x = 15$
Therefore, from the above explanation the correct option is [C] 15.

Note: $x\% $ is written as $\dfrac{x}{{100}}$
$x\% $of b is written as $\dfrac{x}{{100}} \times b$