Question

X and y can do a piece of work in 20 days and 12 days respectively. X started the work alone and then after 4 days y joined him till the completion of work. How long did the work last?

Answer 1

Answer:

10 days

Step-by-step explanation:

Work done by X in 4 days = 1 x 4 = 1 .

20 5

Remaining work = 1 - 1 = 4 .

5 5

(X + Y)'s 1 day's work = 1 + 1 = 8 = 2 .

20 12 60 15

Now, 2 work is done by X and Y in 1 day.

15

So, 4 work will be done by X and Y in 15 x 4 = 6 days.

5 2 5

Hence, total time taken = (6 + 4) days = 10 days

Answer 2

Answer:

6 days

x 20 dys

y 12 days

then lcm of 12 n 20 is 60

so x in 3

y in 5

total in 8

total wrk is 60

x wrks 4 days i.e 3*4=12

60-12=48

then y join

now 3+5=8

rmng wrk 48

divded by 8 so we found tht 6 dys