Kaury has 20 coins in his pocket,all dimes and nickels.The total amount of money in his pocket is $1.60.How much of each type of coin does he have?

Question

How would I set this up and solve the problem?

Answer 1

Hi Ana C

My name is Brenda D

First you have an equation for the total number of coins

Second you have and equation for the Total cost of the nickels and dimes as

x + y = 20

.05x + 0.10y = 1.60

You can eliminate x if you multiply the second equation by negative 20, that’s -20 they you will have

x + y = 20

-x – 2y = -32

Add the two equations to get

-y = -12

Divide both sides by negative 1

-y/-1 = -12/-1

y = 12

To obtain x just substitute 12 for y in the first equation

x + 12 = 20

Subtract 12 from both sides of the equation to get

x = 20 – 12

x= 8

Then you can check both numbers in the second equation

.05(8) + .10(12) = 1.60