A and B can complete a work in 15 days and 10 days respectively. They ...
Let total work be 30 units (LCM of 10 and 15).
In one day, A can do 2 units of work and B can do 3 units of work.
In one day, both A and B can do 5 units of work.
In two days, A and B will complete 10 units of work. Remaining 20 units can be completed by A in 10 days (at rate of 2 units per day).
Hence, whole work will be completed in 12 days.
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A and B can complete a work in 15 days and 10 days respectively. They ...
Given:
A can complete work in 15 days
B can complete work in 10 days
Let's assume that the total work is such that it can be completed in 150 units of work.
So, A can complete 10 units of work in a day (i.e., 150 units of work in 15 days)
Similarly, B can complete 15 units of work in a day (i.e., 150 units of work in 10 days)
Working together, they can complete 25 units of work in a day (10 units by A + 15 units by B)
After 2 days of work, the work completed is 50 units (25 units per day x 2 days)
Now, the remaining work is 100 units (150 units of work - 50 units completed)
As A alone is left to complete the work, he can complete 10 units of work in a day.
So, the total number of days taken by A to complete the remaining work is 100/10 = 10 days
Therefore, the total number of days taken to complete the work is 2 days (initial work done by A and B) + 10 days (remaining work done by A alone) = 12 days.
Hence, the correct answer is option (c) 12 days.
A and B can complete a work in 15 days and 10 days respectively. They ...
Total work = 30 (LCM of 15 nd 10)A = 2(per day work)B = 3(per day work)
A nd B work together for 2 days so (5×2=10)remaining work are 20 unit
now A work alone = 20/2 =10
total days to complete the work are 2+10=12 days