At 9am John was cycling from Point A to Point B. At the same time, Mary was cycling from point B to point A using the same route as John. Cycling at a speed of 4km/h faster than Mary, they would pass each other 300 meter away from the mid point.
a) What time did they pass each other?
b) If John took another 3 minutes to reach Point B, what time would Mary reach Point A?
J
-----> S + 4 km/h
9 am 300 m 300 m |<----3 min----->|
|----------------------|--------|--------|--------------------|
A X m X B
9 am
S km/h <----
M
|<--- 9 min ---->|
4000 m --> 60 min
600 m --> 600/4000 x 60 = 9 min
9 min
|----------------|
9 am 9.09 am
a) It was 9.09 am.
3 X --> X + 300 + 300 3 min versus 9 min
2 X --> 600
X --> 600/2 = 300 m
300 m --> 9 min
1200 m --> 1200/300 x 9 = 36 min
36 min
|--------------|
9 am 9.36 am
b) It was 9.36 am.
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