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2 years ago

Suppose you have an experiment where you flip a coin three times. You then count the number of heads.

Mathematics

1 answer:

jeyben [28]2 years ago

6 0

Answer:

You have a chance of getting any of those.

Step-by-step explanation:

If you were to flip the first coin, and it would be either heads or tails 50% chance.

If you flipped the second coin, without cancelling the first, it would be 25% chance

If you flipped the third coin, without cancelling the first it would be 12.5% chance

(this is all for heads)

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A metallurgist needs to make 12.4 lb. of an 10) alloy containing 50% gold. He is going to melt and combine one metal that is 60%

sergeinik [125]

Now, let's say, we add "x" lbs of the 60% gold alloy, so.. how much gold is in it? well, is just 60%, so (60/100) * x, or 0.6x.

likewise, if we use "y" lbs of the 40% alloy, how much gold is in it? well, 40% of y, or (40/100) * y, or 0.4y.

now, whatever "x" and "y" are, their sum must be 12.4 lbs.

we also know that the gold amount in each added up, must equal that of the 50% resulting alloy.

$\bf \begin{array}{lccclll}
&\stackrel{lbs}{amount}&\stackrel{gold~\%}{quantity}&\stackrel{gold}{quantity}\\
&------&------&------\\
\textit{60\% alloy}&x&0.6&0.6x\\
\textit{40\% alloy}&y&0.4&0.4y\\
------&------&------&------\\
\textit{50\% alloy}&12.4&0.50&6.2
\end{array}$

$\bf \begin{cases}
x+y=12.4\implies \boxed{y}=12.4-x\\
0.6x+0.4y=6.2\\
-------------\\
0.6x+0.4\left( \boxed{12.4-x} \right)=6.2
\end{cases}
\\\\\\
0.6x-0.4x+4.96=6.2\implies 0.2x=1.24\implies x=\cfrac{1.24}{0.2}
\\\\\\
x=\stackrel{lbs}{6.2}$

how much of the 40% alloy? well, y = 12.4 - x.

5 0

3 years ago

A glazier is setting supports in parallel segments to prevent glass breakage during storms. What are the values of x and y? Just

lara [203]

Answer:

m∠y=50°

m∠x=50°

Step-by-step explanation:

we know that

The angles in matching corners are called corresponding angles. When the two lines are parallel Corresponding Angles are equal

m∠y=50° -----> by corresponding angles

and

The angles that are formed on opposite sides of the transversal and inside the two lines are alternate interior angles. When the lines are parallel, the alternate interior angles are equal.

m∠x=m∠y -----> by alternate interior angles

m∠x=50°

therefore

m∠y=50°

m∠x=50°

5 0

3 years ago

I need help with this q7

juin [17]

Answer:

Yes, it is a proportional relationship!

Step-by-step explanation:

7 0

2 years ago

Read 2 more answers

I need help explanation if possible

viva [34]

Answer:

y = 16.

Step-by-step explanation:

The ratio of corresponding sides of similar triangles are the same.

The small and large triangles are similar ( - that is corresponding angles are congruent).

So 2/(2+8) = x / 20

2/10 = x/20

10x = 40

x = 4.

Therefore y = 20 -4 = 16.

3 0

1 year ago

The hardcover version of a book weighs 7 ounces while its paperback version weighs 5 ounces. Forty-five copies of the book weigh

konstantin123 [22]

Answer:

33 copies were paperback and 12 were hardcover.

Step-by-step explanation:

Let h represent the number of hardcover copies and p represent the number of paperback copies.

We know that the total number of copies was 45; this gives us the equation

h+p = 45

We know that each hardcover copy is 7 ounces; this gives us the expression 7h.

We also know that each paperback copy is 5 ounces; this gives us the expression 5p.

We know that the total weight was 249 ounces; this gives us the equation

7h+5p = 249

Together we have the system

$\left \{ {{h+p=45} \atop {7h+5p=249}} \right.$

We will use elimination to solve this. First we will make the coefficients of the variable p the same; to do this, we will multiply the top equation by 5:

$\left \{ {{5(h+p=45)} \atop {7h+5p=249}} \right. \\\\\left \{ {{5h+5p=225} \atop {7h+5p=249}} \right.$

To eliminate p, we will subtract the equations:

$\left \{ {{5h+5p=225} \atop {-(7h+5p=249)}} \right. \\\\-2h=-24$

Divide both sides by -2:

-2h/-2 = -24/-2

h = 12

There were 12 hardcover copies sold.

Substitute this into our first equation:

12+p=45

Subtract 12 from each side:

12+p-12 = 45-12

p = 33

There were 33 paperback copies sold.

3 0

3 years ago

Read 2 more answers