Places A and are 45 km apart from each other. A car starts from place A and another car starts from place at the same time. If they move in the same direction, they meet in 4 and a half hour and if they move towards each other, they meet in 27 minutes. What is the speed (in km/h) of the car which moves faster?
Answer & explanation
Correct answer: option 2
Let speed of faster car = x km/h
Speed of slower car = y km/h
Relative speed when car moves in same direction = ( x - y ) km/h
Relative speed when car moves in opposite direction = ( x + y ) km/h
According to question ,
\(\frac{45}{x - y }\) = 4.5
( x - y) = 10 --------(1)
Now ,
\(\frac{45}{x + y }\) = \(\frac{27}{60}\)
\(\frac{45}{x + y }\) = \(\frac{9}{20 }\)
( x + y) = 100
( x+ y) = 100 -------(2)
Adding equation 1 & equation 2
2x = 110
x = 55
So , the speed of faster car is 55 km/h .