Four paint brushes-A, B, C and D are used to paint or distort a sheet. A is twice as fast as B, C is twice as fast as D and B is 3/2 as fast as C. A distorts (1/8)th of the sheet, B distorts (1/4)th, C paints (3/8)th and D paints the rest. Only one paint brush can work at a time. It takes a total of 120 hours to paint the sheet. What is the time taken by C and D to paint the sheet?

Four paint brushes-A, B, C and D are used to paint or distort a sheet. A is twice as fast as B, C is twice as fast as D and B is 3/2 as fast as C. A distorts (1/8)th of the sheet, B distorts (1/4)th, C paints (3/8)th and D paints the rest. Only one paint brush can work at a time. It takes a total of 120 hours to paint the sheet. What is the time taken by C and D to paint the sheet? Correct Answer 540

Given:

A is twice as fast as B, C is twice as fast as D and B is 3/2 as fast as C.

Assumption:

Let the time taken by A, B, C and D to fill or distort the sheet be t, 2t, 3t and 6t respectively.

Calculation:

A distorts(1/8)th part of the sheet.

Time taken by A to paint= t × (1/8) = t/8

∴ Total time to paint the sheet = - (t/8) – (2t) (1/4) + (3t) (3/8) + (6t)(1/4)

⇒ 2t = 120 hours

⇒ t = 60 hours

Now,

Time taken by C and D to paint the sheet= 3t + 6t = 9t = 540

∴ The time taken by C and D to paint the sheet is 540 hours.

Related Questions

Paddy transplantation in Punjab is a very hard labor-intensive back-breaking job. In the transplant season, teams of special people swarm the entire rural landscape employed by the farmers and can be seen laboring away in the fields under the hot sweltering sun. Farmer Jagtar Singh has a full-time help at his sprawling farm who goes by the name of Hari, and who hails from Allahabad, UP. During the paddy transplant season, it is up to Hari to rope in his brothers, sons, and cousins from his native village to complete the task well in time. All his people are skillful and masters of the trade and equally efficient at their jobs. So, this past season, this is how the work went. Hari started the work and after 't' hours was joined in by his brother Jaggi. After another 't' hours, Neelu, their cousin, also jumped into the fray. So, after every 't' hours, 1 person kept on joining the team of already working men, and this process kept on continuing till the completion of the work. The last person worked for 't' hours. In the last season, the very same men had completed the same work working 2 shifts of 12 hours all of them working simultaneously owing to some peculiar weather conditions and time constraints. Jagtar Singh is a fair and just paymaster which is why he faces no labor shortage at this crucial time and which is why the whole 'Hari clan' are more than happy to work for him and are at his beck and call. He pays each of them individually proportional to the work done by them. This time around, Hari received 11 times as much as Surinder, his eldest son, who was the last person to join in. In how much time was the work completed?