# What is the ratio of the father's speed to Arunima speed?

66 views

Arunima is picked up by her father by car from college everyday. The college gets over at 4 p.m. daily. One day, the college got over an hour earlier than usual. Arunima started walking towards her house. Her father, unaware of this fact., leaves his house as usual, meets his daughter on the way, picks her up and they reach the house 15 minutes earlier than usual. What is the ratio of the father's speed to Arunima speed?

posted Sep 7, 2017

The father is 9 times faster than Arunima.
.
They are 15 minutes earlier home. As this includes a round trip, the dad picks Arunima 7.5 minutes earlier up than normal.
Arunima has by then been walking for 1 hour + 7.5 minutes = 67.5 minutes.
So what the dad does in 7.5 minutes, Arunima did in 67.5 minutes => 67.5 / 7.5 = 9

Similar Puzzles

Two trains 140 m and 160 m long run at the speed of 60 km/hr and 40 km/hr respectively in opposite directions on parallel tracks. What is the time (in seconds) which they take to cross each other?