SOLUTION: if 3/4 of the pupils were boys and there were 240 girls,how many boys were in the school?

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: if 3/4 of the pupils were boys and there were 240 girls,how many boys were in the school?      Log On


   



Question 825151: if 3/4 of the pupils were boys and there were 240 girls,how many boys were in the school?
Answer by TimothyLamb(4379) About Me  (Show Source):
You can put this solution on YOUR website!
---
N = number of students
b = number of boys
g = number of girls
---
N = b + g
b = (3/4)N
b = (3/4)(b + g)
b = (3/4)(b + 240)
b = (3/4)b + (3/4)240
b - (3/4)b = (3/4)240
(4/4)b - (3/4)b = (3/4)240
(1/4)b = (3/4)240
b = 4(3/4)240
b = (3)240
---
answer:
b = 720
---
Solve and graph linear equations:
https://sooeet.com/math/linear-equation-solver.php
---
Solve quadratic equations, quadratic formula:
https://sooeet.com/math/quadratic-formula-solver.php
---
Solve systems of linear equations up to 6-equations 6-variables:
https://sooeet.com/math/system-of-linear-equations-solver.php