Saved Bookmarks
| 1. |
P and Q can do a piece of work in 10 days while Q and R can do the same work in 12 days and R and P in 15 days. They all work together for 6 days. How long will P take to finish the remaining work?1. 8 days2. 6 days3. 9 days4. 10 days |
||||||||||||||||
|
Answer» Correct Answer - Option 2 : 6 days Given: P and Q can do a piece of work = 10 days Q and R can do the same work = 12 days R and P can do a piece of work = 15 days Concept used: Total work = LCM Formula used: Efficiency = Work/Time Calculation Total work = LCM = 60
⇒ 2(P + Q + R) = 15 ⇒ P + Q + R = 15/2 P, Q, and R work together 6 days Work completed by P, Q, and R together in 6 days = (15/2) × 6 = 45 Remaining work = 60 – 45 = 15 Efficiency of P = Efficiency (P + Q + R) – Efficiency of (Q + R) ⇒ (15/2) – 5 = 5/2 = 2.5 Time taken by P to complete the remaining work = 15/2.5 = 6 days ∴ Time taken by P to complete the remaining work is 6 days |
|||||||||||||||||