Question

Paula wants to add some more tropical fish to her aquarium. She wants to buy some Blue Gouramis, which cost $2.50 each, and some Clown Loaches, which cost $5.50 each. She has room for only 6 more fish and she has $24.00 to spend. How many of each kind of fish can she buy?

Let the number of Blue Gouramis be represented by b and the number of Clown Loaches be represented by c . Write the two equations for the system. The first equation will deal with the number of fish. The second one will deal with cost.

Answer 1

Answer: she can buy 3 Blue Gouramis and 3 Clown Loaches.

Explanation:

Let b represent the number of Blue Gouramis that she can buy.

Let c represent the number of Clown Loaches that she can buy.

She has room for only 6 more fishes. It means that

b + c = 6

She wants to buy some Blue Gouramis, which cost $2.50 each, and some Clown Loaches, which cost $5.50 each. She has $24.00 to spend. It means that

2.5b + 5.5c = 24- - - - - - - - - - - -1

Substituting b = 6 - c into equation 1, it becomes

2.5(6 - c) + 5.5c = 24

15 - 2.5c + 5.5c = 24

- 2.5c + 5.5c = 24 - 15

3c = 9

c = 9/3 = 3

b = 6 - c = 6 - 3

b = 3