Joel and Tom were travelling from town X to town Y which was 210 km apart. Joel set off 1 hour 15 minutes later than Tom but arrived 15 minutes earlier. If the average speed of Tom was 42 km/h, find the average speed of Joel.

Options

A. 50 km/h
B. 60 km/h
C. 65 km/h
D. 70 km/h

Answer

B

Explanation

Tom covered 210 km in `(210)/(42)`
=5 hours
Time taken by Joel to cover 210 km
=5.00 -1.30=3.30 hours
`=3(1)/(2)` hours
`:.` Average speed of Joel `=(210)/((7)/(2))`
`=(210xx2)/(7)=60` kmph