Hello
dave13Apologies for the late reply.
You are absolutely correct here and the original poster has updated the OA to correctly reflect B.
The way I tackled this question is - the relative speed of the car w.r.t the bicycle is 10 mph ( as 40 mph - 30 mph) in the same direction. So in 15 mins, the car will have travelled a distance of 10mph * ( 15/60) hr = 10/4 = 2.5 miles ahead of the bicycle.
Now, the bicycle traveling at 30 mph will take ( 2.5 miles / 30 mph) hrs or (2.5/30)*60 mins = 5 mins to reach that point where the car has halted.
Hence the bicycle travels for a total of 15 mins ( original when both car and bicycle are traveling) + 5 mins to catch up = 20 mins.
Hope this resolves your query! Let me know if you want to discuss some more.
Best,
GLadi
dave13 wrote:
MathRevolution wrote:
[
Math Revolution GMAT math practice question]
A car and a bicycle traveled in the same direction along the equal route at their constant speed rates of 40 miles per hour and 30 miles per hour, respectively. After 15 minutes the car passed the bicycle, the car reaches a waiting point, how long it takes the bicycle to reach the waiting point?
A. 15 min
B. 20 min
C. 25 min
D. 30 min
E. 35 min
hey
pushpitkc where am i wrong ?
Why C is correct answer ? i am getting B
if after 15 minutes the car passed a bike, it means that car covered 1/4 * 60 = 10 miles after overtaking bike
so distance between car and bike is 10 miles
so for bike to reach a waiting point is 1/3*60 = 20 minutes
Bunuel maybe you can explain ?
or you
GMATGuruNY how about you ?
Salsanousi _________________
Regards,
Gladi
“Do. Or do not. There is no try.” - Yoda (The Empire Strikes Back)