SOLUTION: colored copies cost 10cent per copy and white copies cost 5cent per copy. Sandy made 400copies, some of which were colored and the rest white. her total bill was $22.50. how man

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: colored copies cost 10cent per copy and white copies cost 5cent per copy. Sandy made 400copies, some of which were colored and the rest white. her total bill was $22.50. how man      Log On


   

Question 184909: colored copies cost 10cent per copy and white copies cost 5cent per copy.
Sandy made 400copies, some of which were colored and the rest white.
her total bill was $22.50.
how many colored copies and how many white copies did she make?
Answer by jojo14344(1513) About Me  (Show Source):
You can put this solution on YOUR website!

1st condition:
0.10C%2B0.05W=22.50
2nd Condition:
C%2BW=400copeis------->C=400-W, EQN 1
Susbt. EQN 1 in Condition 1:
0.10%28400-W%29%2B0.05W=22.50
40-0.10W%2B0.05W=22.50
40-22.50=0.10W-0.05W
17.50=0.05W----->cross%2817.50%29350%2Fcross%280.05%29=cross%280.05%29W%2Fcross%280.05%29
highlight%28W=350%29
Then as per EQN 1:
C=400-350=highlight%2850=C%29
In doubt? Go back Condition 1:
0.10%2850%29%2B0.05%28350%29=22.50
5%2B17.50=22.50
22.50=22.50
Thank you,
Jojo