Confusing birth and death rate problem.

Question

Each day, the number of human births in the world is 88 thousand less than 3 times the number of deaths. If the population increase in a single day is 244 thousand, determine the number of births and deaths each day. 

Answer 1

Ah, another typo -- "confusing" should be "challenging," so let's go for it!

 

First, re-read the problem until you understand it.  Put it into your own words.  How's this:  
World population increases 244 thousand per day .  The number of births is 88 thousand less than 3 times the number of deaths each day.

 

Translate:

  "World population increases 244 thousand per day"    means

          births - deaths    =   244             (in thousands)

 

  "births is 88 thousand less than 3 times the number of deaths each day"    means

     births =         -88          +          3    *         deaths

 

Now, the easy math:

  Let B = daily number of births in thousands per day

        D = daily number of deaths in thousands per day

 

  B - D =244                 (eq1)

  B   = -88 + 3D            (eq2)

 

Solve (note: I like elimination method; you may use substitution):

   B    -    D     = 244              (eq1)

   B    -   3D    = -88              (from eq2)

 -----------------------    (elimination; subtract equations)

             2D    =  332

              D   =   166             (eq3)

   B    -   D    =   244        (elimination; now add eq3 and eq1; but, we could use either eq)

-------------------------

   B              =    410

 

Checking (very important):

  Is   410 = -88 + 3*166   ?

        410 = 410   ? yes