Free Quiz Query

[Swetha]

Hi,

I tried solving the latest free quiz in the website. For the following question, I calculated the solution as 12 days while the answer given is 4 days. can you explain how it is calculated?

David completes 60% of an assigned task in 8 days and realizes that he will be behind schedule at the present rate. He takes the assistance of his younger brother Ron who is one-third as efficient as David is and completes the assigned task on schedule. How many days did David and Ron work together?

[ksb]

Hi

The question asked is how long did David and Ron work together?

The total work got over in 12 days. However, of the 12 days, David worked alone for 8 days and therefore, the duo worked together for only 4 days and hence the correct answer is 4 days

K S Baskar
Faculty - 4gmat

[Vens]

David's one day's work is 60%/8.(=A)
Rons's one Day's work is (60%*3)/8 (=B) (As Ron is one third efficient as David is. This is time and work problem, hence they are inversly proportional.)

Now we can have Their combined work per day which is A+B. i.e. 10% of the work per day. And 40 % work is left. So 4 days would be required.

[shaji]

Ven:

Please reproduce the question entirely. I did not find the question in the free quiz.
Shaji.

I'am sorry. No I found the question. Its from an old quiz.The solution is already in the forum .

Shaji