SOLUTION: Hi joey had some 20cent and ten cent coins.when she used one third of them she hsd $9.60 left. She used half as many 20cent coins as tencent coins. how many 10cent and 20cents

Algebra ->  Customizable Word Problem Solvers  -> Misc -> SOLUTION: Hi joey had some 20cent and ten cent coins.when she used one third of them she hsd $9.60 left. She used half as many 20cent coins as tencent coins. how many 10cent and 20cents       Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 1049329: Hi
joey had some 20cent and ten cent coins.when she used one third of them she hsd $9.60 left. She used half as many 20cent coins as tencent coins.
how many 10cent and 20cents coins did she use.
thanks
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
let t = no. of 20 cent coins
let d = no. of 10 cent coins
:
Do this in cents, $9.60 = 960 cents
:
joey had some 20cent and ten cent coins.
when she used one third of them she hsd $9.60 left.
Then she has 2/3 left, therefore
2%2F3(20t + 10d) = 960
Multiply by 3, to get rid of the fraction
2(20t + 10d) = 3(960)
40t + 20d = 2880
:
She used half as many 20cent coins as ten cent coins:
t = 1%2F2d
d = 2t
:
how many 10cent and 20cents coins did she use.
In the 1st equation, replace d with 2t
40t + 20(2t) = 2880
40t + 40t = 2880
t = 2880/80
t = 36 ea 20 cent coins
then
d = 2(36)
d = 72 ea 10 cent coins
:
;
:
See if this checks out
.20(36) + .10(72) = 14.40
2%2F3*14.40 = $9.60