Question 4324
This is a good problem to write two equations in two variables.

Let x = number of 23 cent stamps
    y = number of 37 cent stamps


Total of the stamps is 80, so x + y = 80.
Value of the stamps is $25 or 2500 cents, so 23x + 37y = 2500


To eliminate the x, multiply both sides of the first equation by -23.
-23x - 23y = -23(80)= -1840
+23x + 37y = 2500


Add the equations together
14y = 660


Divide both sides by 14, giving a value of y that does not come out even.
y = 660/14 = 47.142857. . .


This means that the MAXIMUM number of 37 cent stamps = 47  FINAL ANSWER!! 


As a check, subtract 80 - 47 = 33 of the 23 cent stamps.  The total value of the stamps is
47(37) = $17.39
33(33) = $ 7.59
Total  = $24.98  Only $.02 left out of the $25.


R^2 at SCC