Question

If 10% of x = 20% of y, then x: y is equal to
A. 1: 2
B. 2: 1
C. 5: 1
D. 10: 1

Answer 1

Hint: The value of 10% of x =$ {\dfrac{{10}}{{100}} \times x}$ and the value of 20% of y =${\dfrac{{20}}{{100}} \times y }$. Equate these equations to find the ratio x: y.

Complete step-by-step answer:
We have been given-
10% of x = 20% of y
We can write the above equation as-
$ {\dfrac{{10}}{{100}} \times x}$ = ${\dfrac{{20}}{{100}} \times y }$
Solving further, we get-
$  x \times \dfrac{1}{{10}} = y \times \dfrac{2}{{10}} $
$   \Rightarrow x = 2y $
$   \Rightarrow \dfrac{x}{y} = \dfrac{2}{1}$
$   \Rightarrow x:y = 2:1 $
Therefore, the ratio of x: y is 2: 1. Hence, the option (B) is correct.

Note: Whenever such types of questions appear, then write the things given in question. Using the condition, 10% of x = 20% of y, and converting it in the form $ {\dfrac{{10}}{{100}} \times x}$ = ${\dfrac{{20}}{{100}} \times y }$, solve it and find the ratio of x: y.