Anita can cover a sure separation in 1 hr 24min by covering two-third of the…
2025
Anita can cover a sure separation in 1 hr 24min by covering two-third of the separation at 4km/hr and the rest at5 km/hr. Find the aggregate separation.
- A.
6 km
- B.
9 km
- C.
8 km
- D.
2 km
Attempted by 3 students.
Show answer & explanation
Correct answer: A
Step-by-Step Solution
To find the aggregate separation (total distance), we use the basic relationship: Time = Distance / Speed.
Define Variables:
Let the aggregate separation (total distance) be x km.
First part of the journey: Distance = (2/3)x, Speed = 4 km/hr.
Second part of the journey: Distance = x - (2/3)x = (1/3)x, Speed = 5 km/hr.
Convert Total Time to Hours:
Total time = 1 hour 24 minutes.
24 minutes = 24/60 hours = 0.4 hours.
Total time = 1 + 0.4 = 1.4 hours, which is 14/10 = 7/5 hours.
Set up the Equation:
Total Time = Time1 + Time2
7/5 = ((2/3)x / 4) + ((1/3)x / 5)
7/5 = x/6 + x/15
Solve for x:
Find a common denominator for the right side (30):
7/5 = (5x + 2x) / 30
7/5 = 7x / 30
Multiply both sides by 30/7:
(7/5) * (30/7) = x
x = 6.
The aggregate separation is 6 km.