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Anyone know the answer for this problem??

Anyone know the answer for this problem??-example-1
User Grzechoo
by
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2 Answers

6 votes

Answer:

20%.

Explanation:

I = PRT

300 = 3000*R * 0.5

300 = 1500R

R = 300 / 1500

R = 3/15 = 1/5

As a percentage it is 100 * 1/5

= 20%.

User Khtad
by
8.5k points
4 votes

Answer: 20%

Step-by-step explanation: Notice that in this problem we're asked to find the interest rate not the interest so our answer will be a percent rate of interest.

Let's start this problem by writing the interest formula shown below.

Interest = principal · rate · time

Now we fill in the formula.

The interest earned is $300 so we substitute 300 into the formula.

The principal is the amount invested or $3,000.

We don't know the rate so we can use the variable r.

The time is 0.5 which is equivalent to 1/2

so we can substitute 1/2 in for t.

So we have the equation 300 = (3,000)(r)(1/2).

Simplifying on the right side of the equation, 3,000 · 1/2 is 1,500.

So we have 300 = 1,500r

Now to solve for r since r is being multiplied by 1,500, we need to divide by 1,500 on both side of the equation.

On the right side of the equation, the 1,500's cancel and we have r and on the left side of the equation we have 300 divided by 1,500 or 0.2.

This means that 0.2 = r.

Remember however that the interest rate is a percent so we need to change our decimal to a percent by moving the decimal point 2 places to the right to get 20%. So the interest rate is 20%.

User Saskia
by
8.9k points

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