Some friends are traveling in a car. They were halfway to their destination before the car broke down. Now they have to push the car to reach the closest repairing shop. If 3 boys pushed the car they reach the shop in 4 hours and if 5 girls push the car then they reach the shop in 7.2 hours. How long will it take if the 2 boys and 4 girls push the car together?
Some friends are traveling in a car. They were halfway to their destination before the car broke down. Now they have to push the car to reach the closest repairing shop. If 3 boys pushed the car they reach the shop in 4 hours and if 5 girls push the car then they reach the shop in 7.2 hours. How long will it take if the 2 boys and 4 girls push the car together? Correct Answer 3.6 hours
Given:
3 boys can push the car to the shop in = 4 hours
5 girls can push the car to the shop in = 7.2 hours
Formula used:
Total work done = Total time taken to complete the work × Efficiency
Calculations:
1 hour's work of 3 boys = 1/4
1 hour's work of 5 girls = 1/7.2
1 hour's work of 2 boys = 1/6
1 hour's work of 4 girls = 1/9
1 hour's work of 2 boys and 4 girls together
⇒ (1/6) + (1/9)
⇒ (3/18) + (2/18)
⇒ 5/18
⇒ 1/3.6
∴ 2 boys and 4 girls together can push the car to the shop in 3.6 hours
⇒ 36/(6 + 4)
⇒ 36/10
⇒ 3.6
∴ 2 boys and 4 girls together can push the car to the shop in 3.6 hours
