Question

A car P leaves City C at 7 AM and reaches City D at 11 AM. Another car Q leaves City D at 9 AM and reaches City C at 12:30 PM.
At what time will the two cars cross each other?

• A. 36 min
• B. 36 min
• C. 46 min
• D. 66 min
• E. 56 min

Answer 1

The correct option is E

56 min

Let the distance between the cities be ‘x’km.
The cars cross each other 'y' hours after 9 AM.

P covers x in 4 hrs.

Q covers x in $\frac{7}{2}$ hrs.

Speed of P = $\frac{x}{4}$

Speed of Q = $\frac{2x}{7}$

$\therefore \frac{x(y+2)}{4}+\frac{2xy}{7}=x$

y = $\frac{14}{15}$ hr or 56 min