Taliyah has 174 coins in her collection of dimes and nickels. The total value of the collection is $15.20. How many dimes does she have in her collection?

130 dimes

Step-by-step explanation:

A nickel is worth 5 cents = 0.05n

A dime is worth 10 cents = 0.10d

Taliyah has 174 coins in her collection of dimes and nickels.

n + d = 174

n = 174 - d

The total value of the collection is $15.20.

0.05n + 0.10d = $15.20

We substitute 174 - d for n

Hence:

0.05(174 - d) + 0.10d = 15.20

8.7 - 0.05d + 0.10d = 15.20

- 0.05d + 0.10d = 15.20 - 8.7

0.05d = 6.5

d = 65/0.05

d = 130 dimes

The number of dimes she has in her collection is 130 dimes