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3 years ago

Serena invests $2500 for 3 years and 6 months and earns $328.13. What was the rate of interest? Explain how you solved.

Mathematics

1 answer:

NARA [144]3 years ago

6 0

Answer:

4.38%

Step-by-step explanation:

<em>Assuming simple interest</em>, we start by writing the formula for simple interest.

$SI=Prt$

Where

SI is the interest amount (328.13)

P is the principal amount (2500)

r is the rate of interest (what we need to find)

t is the time, in years (t = 3)

Since we want rate of interest, we re-arrange the formula to get r in terms of the other variables. Shown below:

$SI=Prt\\r=\frac{SI}{Pt}$

Now we simply plug-in the information we know and find r:

$r=\frac{328.13}{(2500)(3)}\\r=0.0438$

To convert into percentage, we multiply by 100:

r = 0.0438 * 100 = 4.38%

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Gemiola [76]

Step-by-step explanation:

to round 4.645 to the nearest whole number consider the tenths’ value of 4.645, which is 6 and equal or more than 5. Therefore, we have to round up: the whole number part of 4.645, 4, increases by 1 to 5, and the decimal point and all digits (.645) are removed.

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2 years ago

A home gardener estimates that 18 apple trees will produce an average yield of 80 apples per tree. But because of the size of th

aliina [53]

19 trees should be planted to maximize the total

<h3>How many trees should be planted to maximize the total</h3>

From the question, we have the following parameters:

Number of apples, x = 18

Yield, f(x) = 80 per tree

When the number of apple trees is increased (say by x).

We have:

Trees = 18 + x

The yield decreases by four apples per tree.

So, we have

Yield = 80 - 4x

So, the profit function is

P(x) = Apples * Yield

This gives

P(x) = (18 + x) *(80 - 4x)

Expand the bracket

P(x) = 1440 - 72x + 80x - 4x^2

Differentiate the function

P'(x) = 0 - 72 + 80 - 8x

Evaluate the like terms

P'(x) = 8 - 8x

Set P'(x) to 0

8 - 8x = 0

Divide through by 8

1 - x = 0

Solve for x

x = 1

Recall that:

Trees = 18 + x

So, we have

Trees = 18 + 1

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Trees = 19

Hence, 19 trees should be planted to maximize the total

Read more about quadratic functions at:

brainly.com/question/12120831

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11 months ago

Rationalise the denominator.<br>1/√5+√2

Pani-rosa [81]

Answer:

Exact Form:

√5 + 5√2

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Decimal Form:

1.86142715

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Step-by-step explanation:

N/A

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2 years ago

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What is 3,920,000,000,000 in scientific notation? 3.92×1010 3.92×1012 3.92×10−10 3.92×10−12

kumpel [21]

Writing in scientific notation is writing in power form.

Writing in power form is usually in the form:

X.y × 10ⁿ

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Answer :

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Hope I helped :)

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3 years ago

all unicorns on rainbow island are either green or yellow. every time the clock strikes midnight the unicorns change their color

Oksi-84 [34.3K]

77 unicorns, because yesterday the ratio was 6:5 and today it is 3:4. If you add the numbers for both ratios together, you get 11 and 7. Finding the LCM of these two gives 77 (because 7 and 11 are both prime).

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e.g. I have 100 fruits. The ratio of apples to oranges is 2:3. How many apples are there?

To solve this you'd add 2 and 3 (5), divide 100 by 5 (20), multiply that by 2 (40) because that's the ratio of apples to oranges.

In this case, you do the reverse. So If I have 77 unicorns, then yesterday there were (77/11 = 7, 7*6= 42, 7*5= 35) 42 green unicorns and 35 yellow. The sum of 42 and 35 is 77. If you do this process with the other ratio you'll get similar results as well.

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2 years ago