math question

Question

Jaime has 29 coins. Some are dimes and some are quarters. If the coins are worth $5.30, how many are dimes?

Answer 1

You can solve this problem with a system of equations.

 

(1) x + y = 29

(2) 0.1x + 0.25y = 5.30

 

Equation 1 represents the total number of coins Jaime has in her possession (x = dimes, y = quarters).

Equation 2 represents the total value of Jaime's coins.  

You can solve this with substitution.

 

x + y = 29

x = 29 - y

 

0.1(29 - y) + 0.25y = 5.30

2.9 - 0.1y + 0.25y = 5.30

2.9 + 0.15y = 5.30

0.15y = 2.40

y = 16 quarters

 

x + y = 29

x + 16 = 29

x = 13 dimes

 

Jaime has 13 dimes.