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
For problem #2, you correctly set up the equation 128 = x(800). To find the value of x, you need to divide both sides of the equation by 800. By simplifying, you get:
x = 128/800
x = 0.16
Since the question asks for the percentage, you need to multiply the result by 100:
x = 0.16 * 100
x = 16%
So, you are correct. The solution is that 128g is 16% of the 800g solution.
For problem #3, the equation should be set up as:
Principal (5000) = Rate (r) * Time (4 years)
The interest earned (400) is not included in this equation because it is the result of the interest rate over the given period of time. By rearranging the equation, you can solve for the interest rate (r):
r = Principal / Time
r = 5000 / 4
r = 1250
So, the interest rate per year is 1250.
For problem #4, you set up the equation correctly as:
72 = 0.12x
To solve for x (the paycheck amount), divide both sides of the equation by 0.12:
x = 72 / 0.12
x = 600
So, the paycheck amount is $600.
I hope this clarifies the solutions for you! Let me know if you have any further questions.