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2 years ago

Giuliana has 22 quarters and dollar coins worth a total of $10.75.

2 answers:

7 0

Use the letters q and d to represent # of quarters and # of dollars.

q + d = 22 coins.

$0.25q + $1.00d = $10.75 Mult. this by 100 to eliminate fractions:
25q + 100d = 1075

Subst. q = 22 - d into the 2nd equation:

25 (22 - d) + 100 d = 1075

550 - 25d + 100d = 1075
550 + 75d = 1075
75 d = 525
d = 7

q + d = 22, so if d = 7, then q = 22-7, or q=15.

There are 15 quarters and 7 dimes.

Ad libitum [116K]2 years ago

4 0

Let

q------> the number of quarters coins

d------> the number of dollars coins

we know that

$1\ quarter=\$0.25$

$q+d=22$

$q=22-d$ ------> equation A

$0.25q+d=10.75$ -----> equation B

substitute equation A in equation B

$0.25[22-d]+d=10.75$

therefore

the answer is the option

$0.25[22-d]+d=10.75$

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Step-by-step explanation:

The time of the finishers in the New York City 10 km run are normally distributed with a mean,μ = 61 minutes and a standard deviation, σ = 9 minutes.

(a)

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Then the standard deviation of the random variable X is:

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Compute the expected value of Z as follows:

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The mean of Z is 0.

Compute the variance of Z as follows:

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The variance of Z is 1.

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2 years ago

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Answer:

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Step-by-step explanation:

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<h2>Answer:</h2>

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The range of a function is the set of all the values that is attained by the function.

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