Question

At the market, 5 light bulbs cost $9. How much do 7 light bulbs cost?

a) $11.20
b) $12.60
c) $14.40
d) $16.80

Answer 1

To find out how much 7 light bulbs cost, we can set up a proportion with the given information. Since 5 light bulbs cost $9, we can solve for the cost of 7 bulbs by setting up a proportion.

Step-by-step explanation:

To find out how much 7 light bulbs cost, we can set up a proportion with the given information. Since 5 light bulbs cost $9, we can write:

5 bulbs = $9

7 bulbs = ?

We can solve for the cost of 7 bulbs by setting up a proportion:

5 bulbs / $9 = 7 bulbs / x

Cross-multiplying, we get:

5x = 7 * $9

Simplifying, we have:

5x = $63

Dividing both sides by 5, we find that x = $12.60.