Correct Answer - Option 2 : 4 days
Given:
Time taken to complete the work by A = 6 days
Time taken to complete the work by B = 8 days
Formula used:
Total work = Efficiency × Time
Calculation:
LCM of 6 and 8 = 24 units = Total work
Efficiency of A = 24/6 = 4 units/day
Efficiency of B = 24/8 = 3 units/day
Work done by A and B together for 3 days = (3 × 7) = 21 units
Remaining work = (24 – 21) units = 3 units
Efficiency of C = 3/2 units = 1.5 units/day
3/4 of the total work = (3/4) × 24 units
⇒ 18 units
Required time taken by B and C = 18 ÷ (3 + 1.5)
⇒ 4 days
∴ Required time taken is 4 days