Question

Four cans of paint will cover 480 ft squared. How many cans will be needed to cover 840 ft squared?
This is a section where a calculator is not allowed.
I need to know how to get the answer. I am trying to check my eigth grade dauthers practice math and I have the answer key, but I am having trouble working the problems out so that I can show her how to get the answer.
The choices are:
A. 8 cans B. 7 cans C. 5 cans D. 3cans

Answer 1

four cans for 480 ft..so by unitary method ..by one can you can cover 480/4 ft squared or for 1 ft squared you need 4/480 cans therefore for 840 ft squared you need 4/480*840=7 cans

Answer 2

So what exactly am I doing to get the answer?

Answer 3

you have to use unitary method to get the answer...

Answer 4

I hate to sound slow, but what exactly is unitary method. Are you referring to ft2?

Answer 5

no it can be explained as like to cover 480 ft squared we need 4 cans so just for 1 ft2 we need 4/480 cans therefore for 840 ft squared we need 4/480*840= 7