Ratio and proportion

nidhis.1408 wrote:3 machines have a productivity ratio of 1:2:5. all 3 machines are working on a job for 3 hours. at the beginning of the 4th hour, the slowest machine breaks. it is fixed at the beginning at hour 7, and begins working again. the job is done in 9 hours. what was the ratio of the work performed by the fastest machine to the work performed by the slowest?

In the first 3 hours, Slowest Machine will yield '1' amount of job, whereas fastest machine will yield '5' amount of job.

In 3rd 3 hour block(7th+8th+9th), Slowest Machine will yield another '1' amount of job, whereas fastest machine will yield another '5' amount of job.

In 2nd 3 hour block(4th+5th+6th), Slowest Machine will yield '0' amount of job, whereas fastest machine will yield another '5' amount of job.

Total amount of job in 9 hours by Slowest Machine will be equal to 1+1 = 2, & by fastest machine will be equal to 5+5+5 = 15.

=> Ratio of Output of Fastest machine to slowest machine will be equals to 15/2.

1:2:5 is the productivity ratio
slowest:medium:fastest

Find the hrs of working:
1:2:5 works for 3 hrs
then
2:5 works for 3hrs
then finally
1:2:5 work for 3hrs

So to sum it up: 1:2:5 works for 6 hrs & 2:5 works for 3 hrs

1 : 2 : 5
6 hrs : 2*9 hrs : 5*9 hrs

Fastest / Slowest required
45/18
Simply
5/2

nidhis.1408 wrote:3 machines have a productivity ratio of 1:2:5. all 3 machines are working on a job for 3 hours. at the beginning of the 4th hour, the slowest machine breaks. it is fixed at the beginning at hour 7, and begins working again. the job is done in 9 hours. what was the ratio of the work performed by the fastest machine to the work performed by the slowest?