- 16 : 5
- 5 : 16
- 8 : 5
- 5 : 8
- 6 : 5
Option 1 : 16 : 5
Let a class A worker complete the work in ‘a’ days and a class B worker complete the work in ‘b’ days
⇒ Amount of work done by a class A worker in 1 day = 1/a
⇒ Amount of work done by a class B worker in 1 day = 1/b
⇒ Amount of work done by 5 class A and 4 class B workers in 1 day = 5/a + 4/b = 1/4
⇒ 20/a + 16/b = 1 → 1
So, they would have completed the work in 4 days if the strike did not happen. But, it takes 4 days 4 hours and 48 min due to the strike
Class A workers work for 4 days 4 hours 48 min whereas class B workers work for 3 days 4 hours 48 min
⇒ 4 hours 48 min = (4/24) + {48/(60 × 24)} = 0.2 day
⇒ Total amount of work done = 4.2 × (5/a) + 3.2 × (4/a)
⇒ 1 = 21/a + 12.8/b → 2
Comparing equations 1 and 2
⇒ 21/a + 12.8/b = 20/a + 16/b
⇒ 1/a = 3.2/b
⇒ a/b = 1/3.2
Efficiency ∝ 1/Time taken
∴ Ratio of their efficiencies = 3.2 : 1 = 16 : 5