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A and B can complete a job in 24 days working together. A alone can complete it in 32 days. Both of them worked together for 8 days and then A left. The number of days B will take to complete the remaining job is:

Solution

✅ Correct Option: 2

A and B together complete the job in 24 days, so their combined rate is 124\frac{1}{24} of the job per day.

A alone completes the job in 32 days, so A's rate is 132\frac{1}{32} of the job per day.

B's rate = (A and B together) - (A alone)

B′s rate=124−132B's \ rate = \frac{1}{24} - \frac{1}{32}

Finding common denominator (LCM of 24 and 32 is 96):

=496−396= \frac{4}{96} - \frac{3}{96}

=196= \frac{1}{96} of job per day

Therefore, B alone takes 96 days to complete the full job.


Both A and B worked together for 8 days.

Work done=124×8Work \ done = \frac{1}{24} \times 8

=824= \frac{8}{24}

=13= \frac{1}{3}

They completed 13\frac{1}{3} of the job in 8 days.


Remaining work=1−13Remaining \ work = 1 - \frac{1}{3}

=23= \frac{2}{3}


B works alone on the remaining work. B's rate is 196\frac{1}{96} per day.

Time=23÷196Time = \frac{2}{3} \div \frac{1}{96}

=23×96= \frac{2}{3} \times 96

=1923= \frac{192}{3}

=64= 64 days

Therefore, B will take 64 days to complete the remaining job.

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