Hide all answers
Hide all answers
View all answers
View all answers
Print
Try the Quiz
A painting job can be completed by 6 painters in 20 days. If 6 more painters join the team 4 days after starting work on the job, then how many more days are required to complete the job?
Answer: 8
**Solution:**
Total effort required by 6 painters for 20 days = 6 × 20 = 120 man-days.
Initial effort by 6 painters for 4 days = 6 × 4 = 24 man-days.
Job still requires 120 − 24 = 96 man-days, and there are 12 painters available to do it.
Additional effort required by 12 painters for 96 man-days = 96 / 12 = 8 days.
Thus, 8 more days are required to complete the painting job.
**Alternative Shorter Solution:**
6 painters require 20 − 4 = 16 more days to complete the job.
Therefore, 6 + 6 = 12 painters will require 16 × 6 / 12 = 8 more days to complete the job.
**Food for thought:**
The number of days for the job is inversely proportional to the number of painters. So, is 'number of days × number of painters = constant'?
What assumptions were made to arrive at the solution?
Is something assumed about the output of the painters?
Try the Quiz : __Puzzles & Brain Teasers : Painting Job__
| |