Question
Out of a journey of 360 km, Rahul travels a part by bike at
60 km/h, and the rest by scooter at 40 km/h. If the total time taken by him is 7.5 hours, find the distance travelled by him on the bike.Solution
ATQ,
Let the distance covered by bike be d km.
Then, distance by scooter = 360 - d km
So, d / 60 + (360 - d) / 40 = 7.5
LCM of 60 and 40 = 120
Or, (2d + 3(360 - d)) / 120 = 7.5
Or, (2d + 1080 - 3d) / 120 = 7.5
Or, (1080 - d) / 120 = 7.5
Multiply both sides by 120:
1080 - d = 900
d = 180
Distance covered by bike = 180 km
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