NY Regents Exam   Teasers   IQ Tests   Chemistry   Biology   GK   C++   Recipes   Search <  a href="/cgi/members/home.cgi" class="toplink">Members   Sign off

Print Preview

### Math Puzzles & Brain Teasers

Painting Job

 View Puzzle Solve Puzzle
 Hide all answers   View all answers   Print   Try the Quiz A painting job can be completed by 8 painters in 19 days. If 16 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: 5 Solution: Total effort required by 8 painters for 19 days = 8 × 19 = 152 man-days. Initial effort by 8 painters for 4 days = 8 × 4 = 32 man-days. Job still requires 152 − 32 = 120 man-days, and there are 24 painters available to do it. Additional effort required by 24 painters for 120 man-days = 120 / 24 = 5 days. Thus, 5 more days are required to complete the painting job. Alternative Shorter Solution: 8 painters require 19 − 4 = 15 more days to complete the job. Therefore, 8 + 16 = 24 painters will require 15 × 8 / 24 = 5 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