Wednesday
February 10, 2016

# Homework Help: Math

Posted by marinda on Thursday, June 28, 2007 at 9:40pm.

Here is the math problem.

150 is 75% of what number?

I know the rate is 75 percent and the base is 150. I am looking for the amount. My questions is how to find the answer? Do I divide?

Okay maybe I am missing a huge section as to finding the answer to this question. I went back to my reading and looked at some examples. I looked at the answers to these examples and I am now even more confused. The problem I looked up was, 20% of what number is 50? The answer my class book gave me was R% = 20%, B = “what number,” A = 50. Is that really the answer?

Set up the problem as an algebraic expression. I first converted 75% to a decimal (.75). Then I made the expression from what I knew (150 equals 75 percent of an unknown number).

I represented the unknown number with the variable x.

150=.75x

Since the question asks for the unknown number (x) I knew I had to isolate x. To isolate x I first divided both sides of the equation by .75

150/.75=.75x/.75

The result is...

200=x

Because the .75s on the right cancel out, only x is left.

Feel free to ask if you have any questions about what I did.

Okay I think I see now. If I have any questions I will ask. Thank you so very much :)

You're welcome! Glad I could help. :-)