## Discussion

#### Q.

A is twice as efficient than B and together they can do the same work in as much time as C and D together. If C and D can complete the work in 20 and 30 days respectively working alone, then in how many days can A complete the work alone?

 A. 30 B. 24 C. 18 D. 12

#### Explanation:

A is twice as efficient than B and together they can do the same work in as much time as C and D together. If C and D can complete the work in 20 and 30 days

Let the total work = 60 units

C does 3 and D does 2 units per day

C & D together can complete in 60/5 = 12 days.

The efficiency ratio of A and B = 2 : 1

2 * x = (2 + 1) 12

x = 18 days
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