Consider a scenario in which two trains start at the same time. T
| Consider a scenario in which two trains start at the same time. The speed of 1st train is 75 km/h and the speed of the 2nd train is 90 km/h. If two train travel in same direction, then the number hour it took for the distance between the two trains to be 60 km is _____.
A. 3
B. 3.5
C. 4
D. 4.5
Please scroll down to see the correct answer and solution guide.
Right Answer is: C
SOLUTION
Data:
Speed of 1st train = 75 km/h
Speed of 2nd train = 90 km/h
Distance between train needed = 60 km
Formula:
\({\rm{Speed}} = \frac{{{\rm{Distance}}}}{{{\rm{Time}}}}{\rm{\;}}\)
Calculation:
Relative speed = | 90 km/h – 75 km/h | = 15 km/r
\(15 = \frac{{60}}{{{\rm{Time}}}}\)
∴ Time = 4 hour
∴ time = 4 h
The number of hours it takes for the distance between the two trains to be 60 km is 4 hours.