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2 years ago

19. Tom has 30 coins with a value of $3.30. If they are all nickels and quarters, how many of each kind of coin does

Mathematics

1 answer:

vova2212 [387]2 years ago

4 0

Answer:

n = nickels, q = quarters

Equation 1: n+q=30

Equation 2: 0.05n+0.25q = 3.30

Step-by-step explanation:

From equation 1, n = 30-q

Substitute in Equation 2:

0.05(30-q) + 0.25q = 3.30

1.5 - 0.05q + 0.25q = 3.30

0.2q = 1.8

q = 9

Substitute in new equation:

n = 30-9

n = 21

It is important to note a nickel is worth 5 cents and a quarter is 25 cents. This helps us build the equations.

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Instead of using the values {1,2,3,4,5,6} on dice, suppose a pair of dice have the following: {1,2,2,3,3,4} on one die and {1,3,

ozzi

Step-by-step explanation:

Sample space, S = {(1,1),(1,3),(1,4),(1,5),(1,6),(1,8),(2,1),(2,3),(2,4),(2,5),(2,6),(2,8),(2,1),(2,3),(2,4),(2,5),(2,6),(2,8),(3,1),(3,3),(3,4),(3,5),(3,6),(3,8),(3,1),(3,3),(3,4),(3,5),(3,6),(3,8),(4,1),(4,3),(4,4),(4,5),(4,6),(4,8)}

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3 years ago

If you know 72=9×8,then _is_times as many as_

Leokris [45]

Answer:

10 is 10 times as many as 10

Step-by-step explanation:

7 0

3 years ago

The number of potholes in any given 1-mile stretch of freeway pavement in Pennsylvania has a Normal distribution. This distribut

Iteru [2.4K]

Answer:

83.85% of 1-mile long roadways with potholes numbering between 22 and 58

Step-by-step explanation:

The Empirical Rule states that, for a normally distributed random variable:

68% of the measures are within 1 standard deviation of the mean.

95% of the measures are within 2 standard deviation of the mean.

99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we have that:

Mean = 49

Standard deviation = 9

Using the Empirical Rule, what is the approximate percentage of 1-mile long roadways with potholes numbering between 22 and 58?

22 = 49 - 3*9

So 22 is three standard deviations below the mean.

Since the normal distribution is symmetric, 50% of the measures are below the mean and 50% are above the mean.

Of those 50% which are below the mean, 99.7% of those are within 3 standard deviations of the mean, that is, greater than 22.

58 = 49 + 9

So 58 is one standard deviation of the mean.

Of those which are above the mean, 68% are within 1 standard deviation of the mean, that is, lesser than 58.

Then

0.997*0.5 + 0.68*0.5 = 0.8385 = 83.85%

83.85% of 1-mile long roadways with potholes numbering between 22 and 58

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2 years ago

I need help with a geometry question

Natali [406]

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2 years ago

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2 years ago