March 2017

Daze of Surveys - Problem is Closed

Land surveying depends in large part on logical analysis; this month’s problem gives opportunity to hone that skill. It’s a variation of an old math SurveyDaze3dilemma:

If on average it takes a surveyor-and-a-half a day-and-a-half to complete a mortgage survey-and-a-half, how many days will it take 4 surveyors to complete 19 mortgage surveys?

Determine to the nearest 0.1 day and explain how you arrive at your answer.

And please, no disparaging comments about mortgage surveys.



S D B Total Name Date Comments
10 5 21  Dave Tlusty 17 Mar Correct solution
8 5 19  Richard Stenzel 18 Mar Correct 
6 5 17   Dennis Melichar 19 Mar  Correct 
4 5 15  Joy Zastrow-Mulcahy 20 Mar Correct 
2 5 13  Larry Schmit 22 Mar Correct 
2 5 13  Norm Hanson 25 Mar Correct 
2 5 13  Tom Swenson 11 Apr Correct 
  (What do all these correct soutions tell us about mortgage surveys in Wis...? Hmmm....)

Dennis Melichar's Solution:

This problem can be converted into one that is easy to get your mind around by multiplying the given 1-1/2 data by 2/3 to convert it to 1 surveyor taking 1 day to do 1 job.

Then it is easy to see that it would take 19 days to do the 19 jobs and that 4 surveyors could do the work in 1/4 the time or 4-3/4 days. Now to convert the 1 surveyor time back to the original 1-1/2 surveyor problem multiply the 4-3/4 days by 3/2 to get the answer of 7.125 days.

To check this answer, the messy way, 19 surveys contains 12-2/3 groups of 1-1/2 surveys which takes 1-1/2 days each to complete or 19 days total. Four surveyors can work 4/1.5 or 2-2/3 faster than 1-1/2 surveyors so the 19 surveys can be completed in 19 days divided by 2-2/3 which is 7.125 days.


updated 21 May 17