Question

A body A travels at $20{\text{m s}}^{-1}$ and a body B travels at $30{\text{m s}}^{-1}$. If the distance covered by these bodies is the same, what is the ratio of the time taken by A to the time taken by B?

• A. $2:3$
• B. $1:1$
• C. $3:2$
• D. $4:3$

Answer 1

The correct option is C $3:2$

Given:
Speed of A $=20{\text{m s}}^{-1}$
Speed of B $=30{\text{m s}}^{-1}$
Let the distance covered by the bodies be $d$.
Time taken by A, $t_A=\frac{d}{20}$
Time taken by B, $t_B=\frac{d}{30}$
$⟹\frac{t_A}{t_B}=\frac{\frac{d}{20}}{\frac{d}{30}}$$=\frac{30}{20}=\frac{3}{2}$
Hence, the required ratio is $3:2$.