Two numbers are respectively 20% and 50% of the third number. What percent is the first number of the second ?

A. 10%

B. 20%

C. 30%

D. 40%

Answer: Option D

Solution(By Examveda Team)

Let the 3^rd number is 100
According to the question,
$$\eqalign{ & \,{1^{{\text{st}}}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,{2^{{\text{nd}}}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,{3^{{\text{rd}}}} \cr & 20\,\,\,\,\,\,\,:\,\,\,\,\,\,\,\,50\,\,\,\,\,\,\,\,:\,\,\,\,\,\,\,100 \cr} $$
Required % = $$\frac{20}{50}$$ × 100 = 40%