# math,algebra

posted by
**jasmine20**
.

Can someone help me put this into equations where i can solve them thanks.

Problem #1

Allen bought 20 stamps at the post office in 37cents and 20cents denominations. If the total cost of the stamps was $7.06, how many 37cents stamps did Allen buy?

Problem #2

An 800g solution of acid and water contains 128g of acid. What percent of the solution is acid?

Problem#3

A principle of $5000 was invested in a savings account for 4years. If the interest earned for the period was $400, what was the interest rate per year?

Problem#4

Enrique puts 12% of his monthly paycheck in an IRA. If he invests $72 in his IRA, how much was his paycheck?

1) I can't figure this one out

2) 128 is what percent of 800? Now write that in math terms (is means equals, of means multiply):

128=x(800)

Remember to multiply by 100 at the end because the decimal needs to be in percent form.

3) Principle = Rate x Time

5000=r(4)

4) $72 is 12% of what? The what is the paycheck amount:

72=(0.12)(x)

belinda, thank you for helping me out

now for # 2

what i got was 16 is that correct so then it would just be 16%

#3

how can be 5000=r(4) where does the 400 goes?

#4

i get a crazy number with decimals. i get 14.46