Question

The distance between two cities $A$ and $B$ is $330$ km. A train starts from $A$ at $8$ $a.m.$ and travels towards $B$ at $60$ $km/hr$. Another train stars from $B$ at $9$ $a.m.$ and travels towards $A$ at $75$ km / hr. At what time do they meet ?

• A. $10$ $a.m.$
• B. $10.30$ $a.m.$
• C. $11$ $a.m.$
• D. $11.30$ $a.m.$

Answer 1

The correct option is C $11$ $a.m.$

Total distance between $A$ and $B$=$330$km/ht.

$\because$ A start from $A$ at $8.00$a.m and $B$ at $9.00$a.m

Time span=$1$hour.

$\therefore$ Distance traveled by $A$ in $1$hr=$60$km.

Now distance left when $B$ will start=$(330-60)$km =$270$km

Relating speed of train $A$ and $B$ =$60$km/hr+$75$km/hr

$=135$km/hr

(Speed added because both train traveled towards each others.)

$\therefore$ Time taken to meet $A$ and $B$=$\frac{270km}{135km/hr}=2hr$

$\therefore$ Both train meets at=$9$a.m+$2$hr=$11$a.m