Please help with math word problems.?

Question

Paul invested $5000 in a time deposit. What interest will
he earn for 1 year if the interest rate is 6.5%?

A chemist has 300 milliliters (mL) of solution that is 18%
acid. How many milliliters of acid are in the solution?

Ms. Jordan has been given a loan of $2500 for 1 year. If
the interest charged is $275, what is the interest rate on the loan?

A survey of 400 people found that 66 were left-handed. What percent of those surveyed were left-handed?

The electricity costs of a business decreased from $12,000
one year to $10,920 the next. What is the rate of decrease?

Answer 1

The first one depends on how many times the interest is compounded per year. The formula for this is A = P(1 + r/n)^(n*t) Where P is the principle (what you start with), r is the interest rate (out of 1, not 100), n is the number of times interest is added every year and t is the number of years. If the interest is added every month, you take

5,000 (1 + .065/12)^(12*1)

5,000 (1.005416666)^12

5,000 (1.066971852)

$5,334.86

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Out of 300 mL, if 18% is acid, you simply take

300 mL * .18 acid/mL = 54 acid

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I am not quite sure how to do this one, so im not gonna try and steer you in the wrong direction on accident.

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If 66 out of 400 people are left handed,

66 / 400 = .165 or 16.5%

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12,000 * x% = 10,920 Divide both sides by 10920 and x

12,000 / 10,920 = 1 / x%

1.098901099 = 1 / x% Take the inverse of each

.91 or 91%

This is the percentage that 10,920 is of the original 12,000. That means the decrease is 9%.

Answer 2

Percent literally means per 100. To determine how many of a group or sum are equal to a certain percentage, you multiply the group or sum by the number in front of the % sign and divide by 100.

If you need to calculate what percent a part is of a sum, you calculate the ratio and multiply by 100.

If you need to calculate percent change, you divide the difference by the original amount and multiply by 100.



1) $5,000 * (6.5/100) = $325

2) 300 mL * 18/100 = 54 mL

3) $275/$2,500 = 11%

4) 66/400 = 16.5%

5) ($12,000 - $10,920)/$12,000 = 9%

Answer 3

For the first one we need to know the timeline we are working with, i.e. does this $5000 earn 6.5% interest monthly or just yearly? If yearly you just multiply the $5000 and the 6.5% to get your answer.


For the second one you would just multiply your 300 mL and the 18% and you should get your answer.

#3 is a division problem, as is #4 & #5.

My guess is your chapter was on percentages & rates, and you should be able to compute these extremely simple word problems. they only get harder, so just asking for an answer is not going to help. And i assume your teacher wants to see your work...

Answer 4

Here is the first one.

Paul invested $5000 in a time deposit. What interest will
he earn for 1 year if the interest rate is 6.5%?

I assume interest is compounded annually.

Interest = 5000(6.5%) = 5000*0.065 = $325.00

Answer 5

If something is 40% smaller, you purely subtract 40%. So 40% of 40 energy is 16: you're attempting this with information from multiplying 40 with information from 0.4. the answer might want to be 40 - 16 = 24 A shorter way might want to easily be to multiply with information from 40 with information from 0.6, when you consider that it really is a million-0.4.

Answer 6

5000*0.065=325

300*0.18=54

275/2500=.11 11%

66/400=.165 16.5%

10920/12000=.91
1-.91=.09 9% decrease

Answer 7

5000x.065=$325
300x.18=54ml acid
(275/2500)x100=11%
66/400x100=16.5%
10920/12000x100=91% of total so decrease is 9%