Leaving home at the same time, Amal reaches office at 10:15 am if he travels at 8 km/hr, and at&nbsp;9:40 am if he travels at 15 km/hr. Leaving home at 9:10 am, at what speed, in km/hr, must he&nbsp;travel so as to reach office exactly at 10 am?&nbsp;

CAT 2020 Question Paper | CAT Verbal Ability Slot 1

Question :

Leaving home at the same time, Amal reaches office at 10:15 am if he travels at 8 km/hr, and at 9:40 am if he travels at 15 km/hr. Leaving home at 9:10 am, at what speed, in km/hr, must he travel so as to reach office exactly at 10 am?

Started 3 months ago by Shashank in

0 72

A.
14
B.
11
C.
13
D.
12

Option D is the correct answer.

Explanatory Answer

At 8 km/hr Amal reaches at 10:15 am and at 15km/hr Amal reaches at 9:40 am.
Lets assume the original time takes as T mins and at 15km/hr the time taken would be T-35 mins
Ratio of speeds is inverse of ratio of time.
(8/15) = (T-35/T)

T = 75 mins
Distance = 8 * (75/60) = 10 kms
Time = (50/60) hr
Speed = 10 * (50/60) = 12 km/hr