Two part mixture, algebra beginners exercise

[jarychk]

Two Part Mixture Exercise, typical for beginning algebra students -
but they normally do the work all on paper.

So common a form of exercise that it can be computerized; but the form is also very practical.

This little program takes user input of amount of blend, solution, or mixture in whatever units; concentration of the low, the high, and the result AS PERCENTS concentration;
and when ready, user clicks button to get results. How much to mix of each of the two separate concentrations.


'VARIABLES
Q=0
baj=0
alta=0
R=0
x=0 'output and to be computed

   nomainwin

   WindowWidth = 550+30
   WindowHeight = 410

   UpperLeftX=int((DisplayWidth-WindowWidth)/2)
   UpperLeftY=int((DisplayHeight-WindowHeight)/2)

   statictext #main.statictext1, "Two solutions will be mixed to make", 30, 61, 224, 25
   textbox #main.quant, 270, 56, 80, 25
   statictext #main.statictext3, "units of", 374, 61, 64, 20
   textbox #main.result, 30, 91, 72, 25
   statictext #main.statictext5, "% concentration result.", 118, 96, 144, 20
   statictext #main.statictext6, "The lower concentration, percent is ", 30, 131, 208, 20
   textbox #main.low, 254, 126, 100, 25
   statictext #main.statictext8, "The higher concentration percent is ", 30, 166, 208, 20
   textbox #main.high, 254, 161, 100, 25
   statictext #main.statictext10, "How much of each solution needs to be mixed?", 30, 206, 144, 20
   button #main.button11, "HOW MUCH EACH?", [howmuch], UL, 334, 201, 160, 25
   statictext #main.answ, "ANSWER HERE", 22, 271, 472+30, 50+15
   open "two part mixture (percents)" for window as #main
   print #main, "trapclose [quit.main]"

   print #main, "font ms_sans_serif 10"
   print #main.answ,"!font ms_sans 12 bold"

   wait

[quit.main]
   Close #main
   END


[howmuch]    'Perform action for the button named 'button11'
   'Insert your own code here
   print #main.quant,"!contents? Q"
   print #main.low,"!contents? baj"
   print #main.high,"!contents? alta"
   print #main.result,"!contents? R"
   '
   if Q<=0 or baj<=0 or alta<=0 or R<=0 then
   notice "something wrong in given data"
   wait
   end if
   if R<baj or R>alta then
   notice "something illogical here"
   wait
   end if
'perform computation for x
   numer=R-baj
   denom=alta-baj
   x=Q*(numer/denom)
   'put a limitation on excess accuracy
   let x$=using("##.###",x)
   let x=val(x$)
'put into a variable to be displayed
   answ$=str$(Q-x);" units of ";str$(baj);" % solution and ";str$(x);" units of the ";str$(alta);" % solution."
'show in the answ ext. statictext
   print #main.answ,answ$
   wait



[tsh73]

In this program, LOW = 0% (pure water) really makes sence.
But program prevents it.