A parking lot meter accepts only quarters and dollars. There are 31 coins with a value of $20.50. How many quarters and how many dollars are there?

Question

Introduce a variable expression for each unknown.

Write an equation to solve the problem.

Answer 1

I'd like to guide you toward the solution, and you can study it and learn to do similar setups for similar problems.

 

Let q = # of quarters; therefore # of dollars = 31-q.  Now, we write the VALUE equation:

.25q + 1.00 (31-q) = 20.50

 

The rest is up to you; I view tutoring as guidance and explanation, not doing the whole job for the student.

 

Always remember to check your answer(s).