- #1
nokia8650
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I was struggling with the question below:
Two drivers take part in a race. The faster driver’s average lap time is 1 minute 6 seconds,
and the slower driver’s 1 minute 10 seconds.
Assuming they drive at a constant speed and started together, how long would it take for
the faster to lap the slower driver?
A 18 minutes 9 seconds
B 19 minutes 15 seconds
C 20 minutes 25 seconds
D 38 minutes 30 seconds
E 40 minutes 50 seconds
The correct answer is B - and I can see how this is arrived at, however I do not know why this is correct, as opposed to A:
My working:
4 sec difference in lap times
66 seconds/4 = 16.5 laps
16.5*66 = 18 minutes 9 seconds
Clearly, for the correct answer, rather than 66 seconds/4 = 16.5 laps, you must use 70 seconds (the slower driver's time). Can someone please explain the logic behind this?
Thanks
Two drivers take part in a race. The faster driver’s average lap time is 1 minute 6 seconds,
and the slower driver’s 1 minute 10 seconds.
Assuming they drive at a constant speed and started together, how long would it take for
the faster to lap the slower driver?
A 18 minutes 9 seconds
B 19 minutes 15 seconds
C 20 minutes 25 seconds
D 38 minutes 30 seconds
E 40 minutes 50 seconds
The correct answer is B - and I can see how this is arrived at, however I do not know why this is correct, as opposed to A:
My working:
4 sec difference in lap times
66 seconds/4 = 16.5 laps
16.5*66 = 18 minutes 9 seconds
Clearly, for the correct answer, rather than 66 seconds/4 = 16.5 laps, you must use 70 seconds (the slower driver's time). Can someone please explain the logic behind this?
Thanks