If a car runs at a constant speed and takes 4.5 hrs to run a distance of 225 km, what time will it take to run 150 km?
2 hrs
4 hrs
3 hrs3 hrs
1 hr
Correct answer is C
Let T be the time taken and D is the distance
For the case given in the problem, the distance covered is directly proportional to the time taken i.e D α T
⇒ D = ST where S is the constant speed
D = 225 km and T = 4.5 hrs
∴ 225 = S x 4.5
S = \(\frac {225}{4.5}\) = 50km/hr
When D = 150km
D = ST
150 = 50 \(\times\) T
T = \(\frac {150}{50}\) = 3 hrs
So it will take 3 hrs