Correct Answer - Option 3 : 105
Given:
Efficiency of A = 150% × B
Efficiency of A = 40% × C
Time taken by A and C to complete the work = 20 days
Calculation:
∵ (Efficiency of A)/(Efficiency of B) = 150/100
= 3/2
(Efficiency of A)/(Efficiency of C) = 40/100
= 2/5
∴ Ratio of efficiency of A, B and C = 6 ∶ 4 ∶ 15
Let, the efficiency of A, B and C = 6a, 4a and 15a.
∴ Work done by A and C = Efficiency × No of days of work
= (6a + 15a) × 20
= 21a × 20
= 420a unit of work.
∴ No of days required by B to finish the work = Total work/Efficiency
= 420a/4a
= 105 days