SOLUTION: A bicyclist was going from point A to point B with a speed of 12 km/h. On the way back he increased his speed to 18 km/h and covered the distance in 15 minutes less. What is the di

Question 1107629: A bicyclist was going from point A to point B with a speed of 12 km/h. On the way back he increased his speed to 18 km/h and covered the distance in 15 minutes less. What is the distance between point A and point B?

Found 2 solutions by josgarithmetic, JThomson:
Answer by josgarithmetic(39617) (Show Source): You can put this solution on YOUR website!
Fifteen minutes is the same as one-fourth of an hour.

SPEED TIME DISTANCE AtoB 12 d/12 d BtoA 18 d/18 d DIFFERENCE

Question asks for d, and it is found in solving .
Answer by JThomson(12) (Show Source): You can put this solution on YOUR website!

Let the distance covered by the cyclist in
kilometres be 'd' and time 't'.

Distance = Speed � Time

Distance travelled at a constant speed of 12km/h from A to B is;

d = 12t

Distance travelled on cyclist's return journey is;

d = 18(t-0.25)

* Note that the cyclist increased his speed to 18km/h and therefore covered the same distance 15 minutes less.

15 minutes in hours is 15/60 = 1/4 or 0.25

12t = 18(t-0.25)

12t= 18t-4.5

6t = 4.5

t = 0.75 or 3/4 hours

Distance between points A and B therefore is;

12�0.75 = 9 km or 18�(0.75-0.25) = 18�0.5 = 9km
RELATED QUESTIONS
A relay race required runners to run from Point A to Point B, and then back from Point B... (answered by richwmiller)
A teacher drove halfway from Point A to Point B at 120 km/h and the rest of the way at... (answered by pv=nrt15rcks)
On his way from suburb A to suburb B, the bus driver maintained a speed of 44 km/h. When... (answered by ankor@dixie-net.com)
A man covers distance of 120 km from town A to Town B at an average speed x km/h. If he... (answered by josgarithmetic)
A bicyclist rode from point A to Point B at an average speed of 30 km/hr. Without... (answered by ankor@dixie-net.com)
An automobile travels from point A to point B at a speed of 40 km/h. How fast must it... (answered by malaydassharma)
A bicyclist traveled with a speed of 12 km/h from a camping ground to a station, located... (answered by richwmiller,josgarithmetic)
Matthew drove 20 km at a steady speed to get to the highway. Once on the highway he... (answered by josgarithmetic)
For the first 30 km, the bicyclist drove with a speed of v km/hr. For the remaining 17km... (answered by ankor@dixie-net.com)