Question listed below.

Question

Each day, the number of births in the world exceeds the number of deaths by 40 thousand. The combined number of births and deaths is 272 thousand. Determine the number of births and the number of deaths per day.

Answer 1

Hi Nicholas,

 

Let's begin by assigning letters to represent our two unknowns:

    B = # births per day

    D = # deaths per day

 

Now let's express one our unknowns in terms of the other unknown:

    B = D + 40,000

 

Now let's write an equation to represent the total number of births and deaths in terms of one unknown:

    B + D = 272,000

    (D + 40,000) + D = 272,000

 

Now let's solve for unknown (D):

    (D + 40,000) + D = 272,000

    D + 40,000 + D = 272,000

    2D + 40,000 = 272,000

    2D = 272,000 - 40,000

    2D = 232,000

      D = 232,000/2

      D = 116,000 (# deaths per day)

 

Now let's determine our other unknown (B) in terms of our solved value for D:

    B + D = 272,000

    B + 116,000 = 272,000

    B = 272,000 - 116,000

    B = 156,000 (# births per day)

 

The key to our solution was being able to express one unknown in terms the other unknown, so we could solve for each unknown in turn.

 

Thanks for submitting this problem and glad to help.

 

God bless, Jordan.