Student: A man drives at a speed of 40 miles/hr. His wife left 30 mins. late with 50 miles/hr speed. when will they meet ?
Options:
(A) 1 hours
(B) 2 hours
(C) 3 hours
(D) 4 hours
(E) 5 hours.
Another student: Let's say, hmmm...
In 30 minutes the man would have droven 20 miles, when his wife starts. Now both are driving in the same direction. So speed of wife related to man is 10(50-40) miles/hr. So wife will cover 20 miles in 2 hours to meet the man. Final answer: (B).