Question 52689: i have a jar with 40 coins that consist of dimes and quarters that amount to$ 4.90 how quarters and dimes do you have? Answer by funmath(2933) (Show Source):
You can put this solution on YOUR website! Let the amount of dimes = x
Then the rest of the coins are quarters, let the amount of quarters=40-x
It's often easier to solve these problems in terms of cents; the amount of money you have is the worth of the coin times the amount of the coins.
The amount of money in dimes that he has = 10x
The amount of quarters that he has = 25(40-x)
The total amount of money he has in cents = 490 cents
The problem to solve:
10x+25(40-x)=490
10x+1000-25x=490
-15x+1000=490
-15x+1000-1000=490-1000
-15x=-510
-15x/-15=-510/-15
x=34
The amount of dimes that he has is 34.
The amount of quarters that he has is 40-34=6.
If you want to check your answer, just count it up the wat that you would any money. You'll see that you have $4.90.
(