Question

30
d) 16
X can do a piece of work in 24 days. When he had worked for 4 days, Y joined him If complete work was
finished in 16 days, Y can alone finished the work in -
a) 18 days
b) 27 days
c) 36 days
d) 42 days
If 5 men or 8 women can do a piece of work in 12 days. How many days will be taken by 2 men and 4
women to do the same work -
a) 15 days
b) 13 days c) 13 days
d) 10 days
If 3 men or 4 women can plough a field in 43 days. How long will 7 men and 5 women take to plough it -
a) 10 days
b) 11 days
c) 9 days
d) 12 days​

Answer 1

Answer:

X can complete the work in 24 days.

So, work done by X in 1 day = 1/24th work

Therefore, work done by him in 4 days = 4*1/24 = 1/6th work

Remaining work to be finished by both X and Y = 1 -1/6 = 5/6

They finish it in (16-4) i.e 12 days. Therefore, work done by both in 1 day = (5/6)/12 = 5/ 72.

Now, work done in 1 day by X alone = 1/24

Therefore, work done by Y alone in 1 day = 5/72 - 1/24 = 2/72 = 1/36

Hence, Y alone can finish the work in 1/(1/36 i.e 36 days