SOLUTION: You have 100 coins that are only nickles and dimes. All the coins add up to 7.00. How many nickles do you have? How many dimes to you have?

Algebra ->  Customizable Word Problem Solvers  -> Coins -> SOLUTION: You have 100 coins that are only nickles and dimes. All the coins add up to 7.00. How many nickles do you have? How many dimes to you have?      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 585457: You have 100 coins that are only nickles and dimes. All the coins add up to 7.00. How many nickles do you have? How many dimes to you have?
Answer by checkley79(3341) About Me  (Show Source):
You can put this solution on YOUR website!

.05n+.10d=7
n+d=100
n=100-d
.05(100-d)+.10d=7
5-.05d+.10d=7
.05d=7-5
.05d=2
d=2/.05
d=40 number of dimes.
n+40=100
n=100-40
n=60 number of nickles.
PROOF:
.05*60+.10*40=7
3+4=7
7=7