Question

Sincere is holding 20 coins, all of which are either dimes or quarters. They have a value of $4.10. Determine how many coins of each he is holding.

Answer 1

Answer: 14 Quarters and 6 Dimes

Explanation:

You write out two equations each with 2 unknown variables

Let x = number of dimes

Let y = number of quarters

Two Equations:

y + x = 20

.25y + .10x = 4.10

Now we have two equations with two unkowns so we can substiture

x = 20-y , now plug x back into your 2nd equation

.25y + .10(20-y) = 4.10

.25y + 2 - .10y = 4.10, now solve for y

.15y = 2.10

y = 14, Plug y into your first equation

x + 14 = 20

x = 6

Final Answer: 14 Quarters and 6 Dimes