Question

Anatoliy has a combination of 104 nickels and quarters totaling $22. Which system of linear equations can be used to find the number of nickels, n, and the number of quarters, q, Anatoliy has?

A. n = q = 22
0.05n + 0.25q = 104

B. n + q = 104
5n + 25q = 22

C. n + q = 104
0.05n + 0.25q = 22

D. n + q = 22
5n + 25q = 104

Answer 1

b?

Answer 2

You know for each nickel you have 5 pennies and for every quarter you have 25 pennies. So to see how many nickels and pennies you need to count.

5 pennies times the number of nickels plus 25 pennies times the number of quarters equals 22 dollars.

But 5 pennies is .05 of a dollar and 25 pennies is .25 of a dollar so
.05 * p + .25 * n = 22 dollars.

You also know, physically, in your hand, you have n + q coins that equal 104 in total.

That's it!

Answer 3

C.
Use the following to avoid decimal numbers:
{5 n + 25 q = 2200, n + q = 104} // Solve
{n -> 20, q -> 84}