80% of a number is equal to the $$\frac{{\text{4}}}{{\text{5}}}$$ th of the other number. what is the ratio between the first number and the second number respectively ?

A. 3 : 4

B. 3 : 5

C. 5 : 3

D. None of these

Answer: Option D

Solution(By Examveda Team)

Let the first number be x and second number be y
According to the question,
$$\eqalign{ & 80\% {\text{ of }}x = \frac{4}{5}\,{\text{of }}y \cr & \Rightarrow \frac{{80 \times x}}{{100}} = \frac{{4 \times y}}{5} \cr & \Rightarrow \frac{{4x}}{5} = \frac{{4y}}{5} \cr & \Rightarrow x:y = 1:1 \cr} $$