A can do a piece of work in 12 days. He worked for 6 days and left, and then B finished it in 10 days. If both work together then, in how many days will they finish the same work?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 7.5.
A can do a piece of work in 12 days
So, one day wok of A = 1/12 units
In 6 days he would have done = 6/12 = 1/2 units
The remaining 1/2 is done by B in 10 days
So, B can do the total work in 20 days
The total work in one day by B = 1/12 + 1/20
⇒ (5 + 3)/60
⇒ 8/60 = 2/15
So, together they will take 15/2 days or 7.5 days