Question 59758
PLEASE HELP ME WITH THIS.  THE QUESTION IS "A PERSON HAS 20 COINS IN NICKELS AND DIMES WITH A COMBINED VALUE OF $1.60.  DETERMINE THE NUMBER OF COINS AND WHAT TYPE."  
These are easier to solve in terms of cents to avoid decimals.
Let the number of dimes be: x
Then the amount of money we have in dimes is: 10x (in cents)
The rest of the 20 coins are nickels: 20-x
Then the amount of money in nickels is: 5(20-x)
The total amount of money in cents is: 160
10x+5(20-x)=160
10x+100-5x=160
5x+100=160
5x+100-100=160-100
5x=60
5x/5=60/5
x=12
The number of dimes: x=12
The number of nickels: 20-x=20-12=8
:
Check are 12 dimes and 8 nickels = to $1.60?
12($.10)+8($.05)=$1.60
$1.20+$.40=$1.60
$1.60=$1.60  We're right!
Happy Calculating!!!