A coin collection consists of dimes and nickels. If there are a total of 500 coins valued at $39. how many dimes are there?

There are 280 dimes

Step-by-step explanation:

A nickel is worth 5 cents while a dime is worth 10 cents

Let n be number of nickel

d the number of dimes

n + d = 39

Secondly

$39 is same as 3900 cents

So we have;

10d + 5n = 3900

From first equation;

n = 500-d

Put this in second equation;

10d + 5(500-d) = 3900

10d + 2500-5d = 3900

5d = 3900-2500

5d = 1400

d = 1400/5

d = 280