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2 years ago

Concrete is made by mixing cement, sand, and

Mathematics

2 answers:

Minchanka [31]2 years ago

6 0

Answer:

60 ft.

Step-by-step explanation

The fraction of cement on the concrete

= 5 / (5+9+13)

= (5/27) * 324

= 5 * 12

= 60 ft.

prohojiy [21]2 years ago

5 0

Answer:

Step-by-step explanation:

Sum the parts of the ratio, 5 + 9 + 13 = 27 parts

Divide the amount of concrete by 27 to find the value of one part of the ratio.

324 ÷ 27 = 12 ← value of 1 part of the ratio , thus

5 parts = 5 × 12 = 60 ← cement

9 parts = 9 × 12 = 108 ← sand

13 parts = 13 × 12 = 156 ← gravel

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gabriella wants to tile a room with an area of 320 square feet. the width of the room is 4/5 its length. what are the length and

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$\frac { 4 }{ 5 } \cdot l\cdot l=320\\ \\ \frac { 4 }{ 5 } \cdot { l }^{ 2 }=320\\ \\ { l }^{ 2 }=320\cdot \frac { 5 }{ 4 } \\ \\ { l }^{ 2 }=\frac { 320\cdot 5 }{ 4 } \\ \\ { l }^{ 2 }=\frac { 1600 }{ 4 } \\ \\ { l }^{ 2 }=400\\ \\ \sqrt { { l }^{ 2 } } =\sqrt { 400 } \\ \\ l=20$

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Answer:

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b) We can use the complement rule on this case. Let X the number of shoots successful, we want this probability:

$P(X \geq 1)$

And using the complement rule we have this:

$P(X \geq 1) = 1-P(X$

And P(X=0) correspond to the probability that Julia misses two shots in a row founded on part A so then we have:

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Step-by-step explanation:

Part a

For this case we know that Julia enjoys shooting paper balls into the basket across her office.

She misses the first shot 50% of the time.

Probability that Julia misses the first shot = $\frac{1}{2}$

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Probability that Julia misses the second shot = $\frac{1}{5}$

For this case we need to find the probability of missing two shots in a row

So we can multiple the two probabilities like this

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Part b

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And we can use the complement rule on this case. Let X the number of shoots successful, we want this probability:

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$P(X \geq 1) = 1-P(X$

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$P(X\geq 1) = 1- \frac{1}{10}= \frac{9}{10}$

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