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Home > CAAC > Chapter 8 > Lesson 8.3.3 > Problem 8-116

8-116.

Write and solve an equation (or system of equations) for the situation described below. Define your variable(s) and write your solution as a sentence. Homework Help ✎

Daria has 18 coins that are all nickels and quarters. The number of nickels is 3 more than twice the number of quarters. If she has $1.90 in all, how many nickels does Daria have?

Define your variables.

n = # of nickels
q = # of quarters

Use the information in the problem to set up a system of equations.

2q + 3 = n

0.05n + 0.25q = 1.9

Substitute 2q + 3 in for n.

0.05(2q + 3) + 0.25q = 1.9

Solve for q.

0.1q + 0.15 + 0.25q = 1.9

0.35q = 1.75

q = 5

Substitute 5 into one of the original equations for q.

2(5) + 3 = n

10 + 3 = n

13 = n