Linear equation word problems

Question

1. A man had $185 in five and ten dollar bills. How many of each does he have if he had 7 fives more than tens?

 

 

2. A child has $11.35 in his piggy bank in nickels,quarters,dimes. How many of each does he have if the number of her dimes is half of the number of her nickels and the number of quarters are 5 less than the number of her dimes?

Answer 1

For each part, set variables for the quantities you need to solve for.  Then use those variables to create the appropriate equations based on the problem description.  I will guide you through the first one.  Then I want you to try the second one using the same procedure.

 

1)

 

The man needs to know the amount of five and ten dollar bills he has.  So we set variables for that.

 

Let number of $10 bills = x

Let number of $5 bills = x + 7

 

Create the equation using these variables.  The equation will represent the total amount in dollars he has.

 

10x + 5(x + 7) = 185

 

 

Now solve for x from this equation.