Question

Kate decides to replace all the lights in her college apartment with energy saving light bulbs beginning this month. The packaging says the new bulbs will use 25% less electricity. If Kate's electric bill last month was $12.00 from bulb use alone, project how much Kate's electric bill will be this month for bulb use.

Answer 1

Kate's electric bill will be $9 for this month for bulb use only.

Explanation:

Given:

Electricity bill lass month from bulb use = $12

Using new bulbs percent decrease in electricity = 25%

We need to find this month electric bill for bulb use.

Solution:

First we will find the reduction in bill after using new bulbs.

reduction in bill after using new bulbs can be calculated by percent decrease in electricity using new bulb multiplied by last month Electricity bill from bulb use only.

framing in equation form we get;

reduction in bill after using new bulbs =
`(25)/(100)* 12 =\$3`

Now we will find this month electric bill for bulb use only.

this month electric bill for bulb use only can be calculated by subtracting reduction in bill after using new bulbs from last month electric bill for bulb use only.

framing in equation form we get;

this month electric bill for bulb use only =
`\$12-\$3=\$9`

Hence Kate's electric bill will be $9 for this month for bulb use only.