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Svet_ta [14]
3 years ago
15

Andreas wants to estimate how many fish there are in a lake. One day he catches 20 fish,marks them,and returns them to the lake.

The next day he catches 10 fish of which four are marked. Estimate the number of fish in the lake.
Mathematics
1 answer:
tensa zangetsu [6.8K]3 years ago
8 0

Answer:

50

Step-by-step explanation:

The ratio of marked fish to caught fish is 4:10, we need to solve for x in 20:x, since 4 * 5 = 20, 10 * 5 = x so x = 50 fish.

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To find the fee for three weeks, we need to multiply the fee for one week by 3.
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Subtract:
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Rochy deposited $400 in her checking account. She wrote a check for $400 to pay for her car note. Then , she made another deposi
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Answer:

$500

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Angus has $3,000 he want to invest. What interest rate compounded continuously does an account need to offer so that Angus has $
kaheart [24]

Answer:

The interest rate is 7.58%

Step-by-step explanation:

Compound continuous interest can be calculated using the formula:

A = Pe^{rt}, where

  • A is the future value of the investment, including interest
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  • r is the interest rate  in decimal
  • t is the time the money is invested for

∵ Angus has $3,000 he want to invest

∴ P = 3000

∵ The interest rate is compounded continuously

∵ Angus has $5,500 in 8 years

∴ A = 5500

∴ t = 8

→ Substitute them in the rule above to find r

∵ 5500 = 3000e^{8r}

→ Divide both sides by 3000

∴ \frac{11}{6} = e^{8r}

→ Insert ㏑ in both sides

∵ ㏑( \frac{11}{6} ) = ㏑(e^{8r})

→ Remember ㏑(e^{n}) = n

∴ ㏑( \frac{11}{6} ) = 8r

→ Divide both sides by 8

∴ 0.07576697545 = r

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→ Round it to the nearest hundredth

∴ r ≅ 7.58

∴ The interest rate is 7.58%

3 0
3 years ago
If 2/9 of the students in a school are in 6th grade, then how
sveticcg [70]

Answer:

231

Step-by-step explanation:

\frac{2}{9} =\frac{42}{x}

42÷2= 21

9×21= 189

189 students total

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3 years ago
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Answer:

3/2

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