Click To Get Off-Campus Placement Jobs Info !!!

MindTree Placement Questions & Answers :: MindTree

5.61K

Total Qs: 1+

NA
SHSTTON
33
Solv. Corr.
69
Solv. In. Corr.
102
Attempted
0 M:54 S
Avg. Time

1 / 1

Choose the correct option.

A can do a piece of work in 14 days which B can do in 21 days. They begin together but 3 days before the completion of the work, A leaves off. The total number of days to complete the work is:

A6 3/5

B8 1/2

C10 1/5

D13 1/2

Explanation:

A's 1 day work = $$\frac{1}{14}$$
B' 1 day work = $$\frac{1}{21}$$

A left 3 day before the completion of work.
B's 3 days' work = $$\frac{1}{21} \times 3 = \frac{1}{7}$$
Remaining work = $$1 \times \frac{1}{7} = \frac{6}{7}$$

(A + B)'s 1 day's work = $$\left(\frac{1}{14} + \frac{1}{21}\right) = \frac{5}{42}$$

Now, $$\frac{5}{42}$$ work is done by A and B = 1 day.
or
whole work done by A&B = $$\frac{42}{5}$$
$$\frac{6}{7}$$ part of work done by A and B = $$\frac{42}{5} \times \frac{6}{7} = \frac{36}{5}$$ days.

Hence, total time taken = (3+36/5)days = $$10\frac{1}{5}$$ days.