Two cyclists start from the same place in opposite directions. One goes towards north at 18 kmph and the other goes towards south at 20 kmph. What time will they take to be 47.5 km apart ?

A. $${\text{1}}\frac{1}{4}{\text{ hrs}}$$

B. $${\text{2}}\frac{1}{4}{\text{ hrs}}$$

C. 2 hrs 23 min

D. $${\text{2}}\frac{1}{2}{\text{ hrs}}$$

Answer: Option A

Solution(By Examveda Team)

To be (18 + 12) km apart, they take 1 hour
To be 47.5 km apart, they take :
$$\eqalign{ & {\text{ = }}\left( {\frac{1}{{38}} \times 47.5} \right){\text{ hrs}} \cr & {\text{ = 1}}\frac{1}{4}{\text{ hrs}} \cr} $$