Aptitude - Time and Work - Discussion

It is very simple;

A's 1day work = 1/6.
B's 1day work = 1/8.
A&B&C's 1day work=1/3.

C's 1day work=A+B+C'S 1day work-(A+B's 1day work)=(1/3)-(1/6)-(1/8) = 1/24.

A will do a complete work that is 1 full work in 6 day's means how much work he will do in 3 days given by;

6days--------->1 complete work
3days--------->?

Cross multiply then we get 1/2 work that is half of the work total work done by A.
Similarly, B ' s work done in 3 days is given by;

8 days-------->1 complete work,
3------------------?

Cross multiply we get 3/8 part of 1 complete work done by B.
Similarly, C's part of work is given by;
24 days --------->1 complete work
3 days ------------>?

By cross multiply, we get 1/8.
So,
For 1 complete work they get ------------>3200.
Then for A's (1/2) part of that work------>?
Cross multiply we get 1600.

Similarly for B
1 complete work------->3200
B's (3/8) part of the work--->?
By cross multiply, we get 1200.
Similarly for C.

1 Complete work ------>3200
C's part of (1/8) part of the work--->?
We get by cross multiply 400.

Why we are taking ratio 3 * 3200 * 1/24 where does this 3 come from can anyone explain me?

1/6 * 24 : 1/8 * 24 :1/24 * 24 convert fraction to the whole number.

How 4:3:1 came? Anyone explain me.

The sum of three numbers is 275. If the ratio between the fast and second be 3:7 and that between the second and third be 4:5 then find the second number. Can anyone solve this?

The total work-> 24 {LCM of days}.
A's 1day work->4,
B's 1day work->3,
with the help of C they completed the work in 3 days,
A+B+C=8 {24/3 ie, total work/no.of days to complete}.
4+3+C=8.
C=1.
Then, 3200/8=400.
C does 1unit so C gets 400.

If it does 2units 400 * 2.

Thank you @Sai vinay.

@all.

A takes 6 days to complete the job. So a one day work is 1/6 and for 3 days it is 3/6 ie 1/2.

Similarly for B for 3 days work is 3/8 now A's share is 1/2 of 3200= 1600 B's share 3/8 of 3200=1200.

So C's share 3200--- (1600+1200) = 40.

Option A is the right answer if you perfectly have understood the question.
Here in the question, it is given that A & B undertook to do the work for 3200 then how C can earn his wages from the first day.
Here Supposed A & B if do the work in 3 days then they will able to do - 21 work
But they did it in 3 days with the help of C.

So the method is here that;
For the first two days, A+B do - 14 work.
Then with the help of C they able to finish it in 3 days so A+B+C do last day - 10 work.
That means one-day work of C is - 3.
Then the work ratio of A+B for two days with A+B+C in one day is - 14:10 = 7:5.
Then (3200 ÷12) * 5 = 1250.
Then bye one-day work ratio of A B&C = 4:3:3.
Then (3200÷10) * 3 = 375,
Hence the answer is 375.

Why we need to multiply 3200*1/8?