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2 years ago

There are some books on a shelf and 12 are cookbooks. If 20% are cookbooks, how many books are on the shelf

1 answer:

5 0

If u take 12 divided by .20 you would get 60 because if u think of it as a dinner bill say it is $60.00 and I want to give a 10% tip it would be $6 but if u give a 20% tip u would give $12

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Seven balls are randomly withdrawn from an urn that contains 12 red, 16 blue, and 18 green balls. Find the probability that (a)

UNO [17]

Answer:

a) P=0.226

b) P=0.6

c) P=0.0008

d) P=0.74

Step-by-step explanation:

We know that the seven balls are randomly withdrawn from an urn that contains 12 red, 16 blue, and 18 green balls. Therefore, we have 46 balls.

a) We calculate the probability that are 3 red, 2 blue, and 2 green balls.

We calculate the number of possible combinations:

$C_7^{46}=\frac{46!}{7!(46-7)!}=53524680$

We calculate the number of favorable combinations:

$C_3^{12}\cdot C_2^{16}\cdot C_2^{18}=660\cdot 120\cdot 153=12117600$

Therefore, the probability is

$P=\frac{12117600}{53524680}\\\\P=0.226$

b) We calculate the probability that are at least 2 red balls.

We calculate the probability withdrawn of 1 or none of the red balls.

We calculate the number of possible combinations:

$C_7^{46}=\frac{46!}{7!(46-7)!}=53524680$

We calculate the number of favorable combinations: for 1 red balls

$C_1^{12}\cdot C_7^{34}=12\cdot 1344904=16138848$

Therefore, the probability is

$P_1=\frac{16138848}{53524680}\\\\P_1=0.3$

We calculate the number of favorable combinations: for none red balls

$C_7^{34}=5379616$

Therefore, the probability is

$P_0=\frac{5379616}{53524680}\\\\P_0=0.1$

Therefore, the the probability that are at least 2 red balls is

$P=1-P_1-P_0\\\\P=1-0.3-0.1\\\\P=0.6$

c) We calculate the probability that are all withdrawn balls are the same color.

We calculate the number of possible combinations:

$C_7^{46}=\frac{46!}{7!(46-7)!}=53524680$

We calculate the number of favorable combinations:

$C_7^{12}+C_7^{16}+C_7^{18}=792+11440+31824=44056$

Therefore, the probability is

$P=\frac{44056}{53524680}\\\\P=0.0008$

d) We calculate the probability that are either exactly 3 red balls or exactly 3 blue balls are withdrawn.

Let X, event that exactly 3 red balls selected.

$P(X)=\frac{C_3^{12}\cdot C_4^{34}}{53524680}=0.57\\$

Let Y, event that exactly 3 blue balls selected.

$P(Y)=\frac{C_3^{16}\cdot C_4^{30}}{53524680}=0.29\\$

We have

$P(X\cap Y)=\frac{18\cdot C_3^{12} C_3^{16}}{53524680}=0.12$

Therefore, we get

$P(X\cup Y)=P(X)+P(Y)-P(X\cap Y)\\\\P(X\cup Y)=0.57+0.29-0.12\\\\P(X\cup Y)=0.74$

8 0

3 years ago

Which is the equation of the line that contains points (0, 5) and (5, 8)

AURORKA [14]

<span>Points: (0, 5) and (5, 8)Slope: 3/5 Equation: y = 3/5x+5 in slope intercept form.</span>

7 0

3 years ago

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Help agian plz if u do u will get points

igor_vitrenko [27]

The sales tax is 3.49 I think

3 0

3 years ago

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Me. Watson is making 34.6 fluid once's of red paint and 18.6 fluid ounces of yellow paint to make orange paint. How many 3.5- fl

forsale [732]

Answer: She can fill about 15 3.5- fluid once jars.

Step-by-step explanation:

Given:

Quantity of red paint = 34.6 fluid ounces

Quantity of yellow paint = 18.6 fluid ounces

Total quantity of orange color = (Quantity of red paint )+(Quantity of yellow paint )

= (34.6+18.6) fluid ounces

= 53.2 fluid ounces

Number of 3.5- fluid ounce jars she can fill = (Total quantity of orange color) ÷ 3.5

= 53.2÷3.5 = 15 (approx)

Hence, She can fill about 15 3.5- fluid once jars.

7 0

2 years ago

If the mean of the data set is 84 points, find Haruka's final exam score in chemistry,

Pepsi [2]

The answer is 45 because if you divide 84 and 2 you get 42 and then add 3

8 0

2 years ago

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