Question

Two cars $A$ and $B$ having average speeds of $30$ and $40$ miles/hr respectively are $280$ miles apart. They start moving towards each other at $3$ PM. At what time will they meet?

• A. $5$ pm
• B. $6$ pm
• C. $7$ pm
• D. $8$ pm

Answer 1

Answer: (C)

$7$ pm

Solution:-

$v_A=30miles/hr$

$v_B=40miles/hr$

Let t be the common time after which both cars will meet.

Total distance covered by both cars $=280$ miles (Given)

$\Rightarrow$ distance covered by car $A+$ distance covered by car $B=280$

$\therefore (v_A\times t)+(v_B\times t)=280$

$\Rightarrow$ $30t+40t=280$

$\Rightarrow$ $t=4$ hrs.

Hence, both cars will meet after $4$ hrs.

As both the cars started moving towards each other at $3$ PM.

Therefore, both cars will meet after $4$ hrs, i.e., at $7$ PM.