1 Answers
Option 2 : 360/37 days
Given:
Time to complete the whole work by A and B together = 12 days
Time to complete the whole work by B and C together = 18 days
Time to complete the whole work by A and C together = 15 days
Formula used:
Efficiency = Work Done/Time taken
Calculations:
Let the total work be LCM of 12,18, 15 i.e. 180 units.
Let efficiency of A, B and C be A, B and C respectively.
Efficiency of A and B together,
⇒ A + B = 180/12 = 15 units/day ----(i)
Efficiency of B and C together,
⇒ B + C = 180/18 = 10 units/day ----(ii)
Efficiency of A and C together,
⇒ A + C = 180/15 = 12 units/day ----(iii)
Adding equation (i), (ii) and (iii), we get,
(A + B) + (B + C) + (A + C) = 15 + 10 + 12
⇒ 2A + 2B + 2C = 37
⇒ A + B + C = 37/2 units/day
Time taken by A, B and C to complete the whole work together = 180/(37/2)
⇒ 360/37 days
∴ The time taken by A, B and C to complete the whole work together = 360/37 days