Tapsee and Pannu are great masons and they working alone can build a wall in 10 and 15 days respecti...........

Quant (SSC) Time and work

Tapsee and Pannu are great masons and they working alone can build a wall in 10 and 15 days respectively. Katappa is a labourer and he can demolish the same kind of wall in 4 days. If they all start working together, how many days will the wall be either built or demolished completely?

The wall will be built in 12 days

The wall will be demolished in 12 days

The wall will be built in 12/5 days.

The wall will be demolished in 12/5 days

छोटे Courses बड़े Results

Master Time and work

Prepare through Micro-courses

Try Now

Explanation:

As per the given information, individual efficiency of both Tapsee and Pannu has to be positive and that of Katappa negative.
Therefore, work done by all working together
= 1/10 + 1/15 - 1/4 = -1/12
Clearly, the wall will be demolished in 12 days.