Places A and B are 396 km apart. Train X leaves from A for B and train Y leaves from B for A at the same time on the same day on parallel tracks. Both trains meet after $$5\frac{1}{2}$$ hours. The speed of Y is 10 km/h more than that of X. What is the speed (in km/h) of Y?

A. 41

B. 54

C. 31

D. 56

Answer: Option A

Solution(By Examveda Team)

\[A\xrightarrow{{\,\,\,\,\,\,\,\,\,\,396\,\,\,\,\,\,\,\,\,\,}}B\]
$$\eqalign{ & \frac{{396}}{{A + B}} = \frac{{11}}{2} \cr & X + Y = \frac{{396 \times 2}}{{11}} \cr & X + Y = 36 \times 2 \cr & X + Y = 72 \cr & {\text{Let,}} \cr & X = a \cr & Y = a + 10 \cr & a + a + 10 = 72 \cr & 2a = 62 \cr & a = 31{\text{ km/h}} \cr & Y = 31 + 10 = 41 \cr} $$