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MrMuchimi
3 years ago
11

A motorboat can go 8 miles downstream on a river in 20 minutes. It takes 30 minutes for the boat to go upstream the same 8 miles

. Find the speed of the current
Mathematics
2 answers:
ladessa [460]3 years ago
6 0

Answer:

<em>The speed of the current is </em><em>4 miles/hour</em>

Step-by-step explanation:

Let us assume that,

x = speed of the boat,

y = speed of the current.

We know that,

\text{Speed}=\dfrac{\text{Distance}}{\text{Time}}

A motorboat can go 8 miles <em>downstream</em> on a river in 20 minutes or \dfrac{20}{60} hours.

\Rightarrow x+y=\dfrac{8}{\frac{20}{60}}=\dfrac{8\times 60}{20}

\Rightarrow x+y=24    --------------------------1

It takes 30 minutes for the boat to go <em>upstream</em> the same 8 miles.

\Rightarrow x-y=\dfrac{8}{\frac{30}{60}}=\dfrac{8\times 60}{30}

\Rightarrow x-y=16    ----------------------------2

Subtracting equation 1 and 2,

\Rightarrow x+y-x+y=24-16

\Rightarrow 2y=8

\Rightarrow y=4 miles/hour

sasho [114]3 years ago
3 0

4 miles per hour is the answer

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Step-by-step explanation:

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b. <u>The probability is 0.2029 or 20.29%</u>

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Step-by-step explanation:

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1 0.0002 0.0002

2 0.0016 0.0017

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x Pr[X = x] Pr[X ≤ x]

0 0.0271 0.0271

1 0.1176 0.1447

2 0.2301 0.3748

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5 0.1059 0.9504

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