Jasleen covered a distance of 1560 miles between city P and city Q taking a total of 10 hours. If part of the distance was covered at 120 miles per hour speed and the balance at 160 miles per hour speed, how many hours did she travel at 120 miles per hour?
Jasleen covered a distance of 1560 miles between city P and city Q taking a total of 10 hours. If part of the distance was covered at 120 miles per hour speed and the balance at 160 miles per hour speed, how many hours did she travel at 120 miles per hour?
The correct option is D 1 hr
Let 'x' hours be the time for which Jasleen travelled at 120 miles per hour.
As the total time taken to cover 1560 miles is 10 hours, Jasleen would have travelled (10 - x) hours at 160 miles per hour.
Distance covered at 120 miles per hour = Speed × time = 120 × x = 120x miles
Distance covered at 160 miles per hour = Speed × time = 160 (10 - x) = 1600 - 160x miles
Total distance covered = Distance covered at 120 miles per hour + Distance covered at 160 miles per hour.
Therefore, total distance = 120x + 1600 - 160x
But, we know that the total distance = 1560 miles.
Therefore, 1560 = 120x + 800 - 160x
40x = 40 or x = 1 hour.
1 hr
Let 'x' hours be the time for which Jasleen travelled at 120 miles per hour.
As the total time taken to cover 1560 miles is 10 hours, Jasleen would have travelled (10 - x) hours at 160 miles per hour.
Distance covered at 120 miles per hour = Speed × time = 120 × x = 120x miles
Distance covered at 160 miles per hour = Speed × time = 160 (10 - x) = 1600 - 160x miles
Total distance covered = Distance covered at 120 miles per hour + Distance covered at 160 miles per hour.
Therefore, total distance = 120x + 1600 - 160x
But, we know that the total distance = 1560 miles.
Therefore, 1560 = 120x + 800 - 160x
40x = 40 or x = 1 hour.
