[12 days] A and B can complete a work in 15 days and 10 days respectively. They started doing the work togethe

For Competitive Exams

A and B can complete a work in 15 days and 10 days respectively. They started doing the work together but after 2 days B had to leave and A alone completed the remaining work. The whole work was completed in :

8 days

10 days

12 days

15 days

Explanation:

$\left(A + B\right)$s 1 days work =$ \left(\dfrac{1}{15} +\dfrac{1}{10} \right) $=$ \dfrac{1}{6} $.

Work done by A and B in 2 days =$ \left(\dfrac{1}{6} \times 2\right) $=$ \dfrac{1}{3} $.

Remaining work =$ \left(1 -\dfrac{1}{3} \right) $=$ \dfrac{2}{3} $.

Now,$ \dfrac{1}{15} $work is done by A in 1 day.

$ \dfrac{2}{3} $work will be done by a in 15 $\times \dfrac{2}{3} $ = 10 days.

Hence, the total time taken = $\left(10 + 2\right)$ = 12 days.

Additional Questions

A works twice as fast as B. If B can complete a work in 12 days independently, the number of days in which A and B can together finish the work in :	Answer
A can do a work in 15 days and B in 20 days. If they work on it together for 4 days, then the fraction of the work that is left is :	Answer
A can finish a work in 24 days, B in 9 days and C in 12 days. B and C start the work but are forced to leave after 3 days. The remaining work was done by A in:	Answer
A and B can do a work in 8 days, B and C can do the same work in 12 days. A, B and C together can finish it in 6 days. A and C together will do it in :	Answer
X can do a piece of work in 40 days. He works at it for 8 days and then Y finished it in 16 days. How long will they together take to complete the work?	Answer
A and B can together finish a work 30 days. They worked together for 20 days and then B left. After another 20 days, A finished the remaining work. In how many days A alone can finish the work?	Answer
P can complete a work in 12 days working 8 hours a day. Q can complete the same work in 8 days working 10 hours a day. If both P and Q work together, working 8 hours a day, in how many days can they complete the work?	Answer
Twenty women can do a work in sixteen days. Sixteen men can complete the same work in fifteen days. What is the ratio between the capacity of a man and a woman?	Answer
A, B and C can complete a piece of work in 24, 6 and 12 days respectively. Working together, they will complete the same work in:	Answer
A and B can complete a work in 15 days and 10 days respectively. They started doing the work together but after 2 days B had to leave and A alone completed the remaining work. The whole work was completed in :	Answer

Share with Friends