Question

Amit and Bablu take 40 and 60 days respectively to do a work independently. Case-1: Amit starts alone after 5 days bablu join him. How many more days are required to complete the work.

Answer 1

Answer:

This means the rate of work done by A = 120/40 = 3 units per day

Similarly the rate of work done by B = 120/60 = 2 units per day

Now when both A and B work together on the same work (120 units), the overall rate of work done would be the sum if rates of A and B, i.e., 3+2 units per day or 5 units per day.

Now let both of them work together for ‘x’ number of days after which B quit and A had to work alone at a rate of 3 units per day for the rest of (32-x) days So the problem can be reduced to

5x + 3(32-x) = 120

=> 2x = 24

=> x = 12 days

So the number of days A worked alone = 32-x = 20 days