Question

P is twice efficient than Q, Q is is thrice efficient than R and R does the whole work in 54 days then in how many days P and Q together complete work?
1. 9 days 
2. 5 days 
3. 8 days 
4. 6 days 
5. 7 days 

Answer 1

Correct Answer - Option 4 : 6 days 

Given:

P = 2Q

Q = 3R

R can complete a work in 54 days

Concept used:

If A does a work in n days then 1-day work of A is 1/n

Calculation:

According to question

Let, P's one day work = 6 unit

⇒ Q's one day work = 3 unit

⇒ R's one day work = 1 unit

R can complete work in 54 days 

⇒ Total work = 1 × 54 = 54 unit

⇒ (P + Q) can complete work in = 54/( 6 + 3)

⇒ 54/9

⇒ 6 days 

∴ P and Q together can complete work in 6 days