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A cyclist riding in fog overtakes a man walking at the speed of 3 km/h. If the man could see the cyclist for 4 minutes an up to a distance of 100m, what is the speed of the cyclist in km/h?
A. 1.5
B. 2.5
C. 4.5
D. 5
E. 6
The OA is C.
I try to solve it as follow,
$$Dist=100m\ =\frac{1}{10}km.$$
$$Time=4\min=\frac{1}{15}hours.$$
$$rate=rate\ of\ cyclits\left(x\right)-rate\ of\ walking=x-3.$$
$$Time=\frac{Dist}{Speed}\ \Rightarrow \frac{\frac{1}{10}}{x-3}=\frac{1}{15}\ \Rightarrow x=4.5\.$$
Experts, any suggestion about this PS question? Thanks in advance.
A. 1.5
B. 2.5
C. 4.5
D. 5
E. 6
The OA is C.
I try to solve it as follow,
$$Dist=100m\ =\frac{1}{10}km.$$
$$Time=4\min=\frac{1}{15}hours.$$
$$rate=rate\ of\ cyclits\left(x\right)-rate\ of\ walking=x-3.$$
$$Time=\frac{Dist}{Speed}\ \Rightarrow \frac{\frac{1}{10}}{x-3}=\frac{1}{15}\ \Rightarrow x=4.5\.$$
Experts, any suggestion about this PS question? Thanks in advance.
