A man in a car observes that he can count 41 electric poles in 2 minutes. If each consecutive electric pole is known to be 50 meter apart, what is the speed of the car?
(A) 61 km/h
(B) 60 km/h
(C) 61.5 km/h
(D) 60.5 km/h
(E) 82 km/h
I'm confused how to set up the formulas here. Can any experts help?
A man in a car observes that he can count 41 electric poles
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Hello ardz24.
Let's see your question.
The man saw 41 electric poles and each consecutive electric pole is known to be 50 meter apart, it implies that the man droves for $$d=41\cdot50=2050\ meters.$$ On the other hand, the man droves during 2 minutes. Now using the formula $$d=v\cdot t\ \Leftrightarrow\ \ v=\frac{d}{t}=\frac{2050mts}{2\ \min}=1025\ \frac{mts}{\min}\cdot\frac{1km}{1000mts}\cdot\frac{60\min}{1\ hour}=61.5\ \frac{k}{h}.$$ So, the correct answer is the option C.
I hope this explanation may help you.
I'm available if you'd like a follow-up.
Regards.
Let's see your question.
The man saw 41 electric poles and each consecutive electric pole is known to be 50 meter apart, it implies that the man droves for $$d=41\cdot50=2050\ meters.$$ On the other hand, the man droves during 2 minutes. Now using the formula $$d=v\cdot t\ \Leftrightarrow\ \ v=\frac{d}{t}=\frac{2050mts}{2\ \min}=1025\ \frac{mts}{\min}\cdot\frac{1km}{1000mts}\cdot\frac{60\min}{1\ hour}=61.5\ \frac{k}{h}.$$ So, the correct answer is the option C.
I hope this explanation may help you.
I'm available if you'd like a follow-up.
Regards.
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Isn't the interval between poles the issue ? Between 41 poles there are 40 intervals.EconomistGMATTutor wrote:Hello ardz24.
Let's see your question.
The man saw 41 electric poles and each consecutive electric pole is known to be 50 meter apart, it implies that the man droves for $$d=41\cdot50=2050\ meters.$$ On the other hand, the man droves during 2 minutes. Now using the formula $$d=v\cdot t\ \Leftrightarrow\ \ v=\frac{d}{t}=\frac{2050mts}{2\ \min}=1025\ \frac{mts}{\min}\cdot\frac{1km}{1000mts}\cdot\frac{60\min}{1\ hour}=61.5\ \frac{k}{h}.$$ So, the correct answer is the option C.
I hope this explanation may help you.
I'm available if you'd like a follow-up.
Regards.