Correct Answer - Option 3 :
Both statement 1 and statement 2 together is needed to answer the question.
Given:
P, Q and R alone can complete the work in 12, 18 and 36 days respectively.
The sum of the wages of P and R is Rs. 640
Formula used:
If a person does work in 'n' days then one day work is done by a person = 1/n part of total work.
The wage of a person is directly proportional to the efficiency of a person.
If A and B does work in x and y days respectively, the efficiency will be in the ratio of y : x
Calculation:
The efficiency of P, Q and R will be (1/12) : (1/18) : (1/36)
LCM of (12, 18 and 36) = 36
Then the efficiency of P, Q and R will be in the ratio (1/12) × 36 : (1/18) × 36 : (1/36) × 36
⇒ 3 : 2 : 1
Let the efficiency of P, Q and R be 3k, 2k and k
According to the question,
3k + k = 640
⇒ 4k = 640
⇒ k = 640/4
⇒ k = 160
Now, the wage of P = 3k
⇒ 3 × 160
⇒ Rs. 480
The wage of Q = 2k
⇒ 2 × 160
⇒ Rs. 320
The wage of R = k
⇒ Rs. 160
The wages of P, Q and R together = (480 + 320 + 160)
⇒ Rs. 960
∴ We can say that Both statement 1 and statement 2 together is needed to answer the question.