In a class of 20 students, 40% are boys. 25% of boys and 50% of the girls wear glasses. How many students wear glasses?

There are 15 male teachers in the school. There are 35 female teachers in the school. <br><br>

Alex777 [14]

Answer:

the ratio of make to female teachers is 3:7

4 0

2 years ago

The area of a rectangle is 980 in squared. the ratio of the length to the width is 5 : 4. find the length and the width.

ella [17]

Answer: The length of the rectangle is 35 in.

The width of the rectangle is 28 in.
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Explanation:
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The formula for the area, "A", of a rectangle:

Area (A) = length (L) * width (w) ;

that is: " A = L * w " ;

A = 980 in² (given);

ratio of the length to the width is: " 5 : 4 " (given);

→ Find the length (L) and the width (w).
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→ 980 in² = (5x) * (4x) ;

in which: " 980 in² " is the area of the triangle;

" 5x" = the length (L) of the rectangle, for which we shall solve;

" 4x" = the width (w) of the rectangle, for which we shall solve.
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If we find solve for "x" ; we can solve for "5x" and "4x" (the "length" and the "width", respectively); by plugging in the solved value for "x" ;
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→ 980 in² = (5x) * (4x) ;

↔ (5x) * (4x) = 980 in² ;

→ (5x) * (4x) = (5) * (4) * (x) * (x) = 20 * x² = 20x² ;

→ 20x² = 980 ;

Divide each side by "10" ; by canceling out a "0" on each side of the equation:

→ 2x² = 98 ;

Now, divide each side of the equation by "2" ;

→ 2x² / 2 = 98 / 2 ;

to get:

→ x² = 49 ;

Now, take the "positive square root" of each side of the equation; (since a "length or width" cannot be a "negative value") ;
to isolate "x" on one side of the equation; & to solve for "x" ;

→ ⁺√(x²) = √49 ;

to get:

→ x = 7 ;
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Now, we can solve for the "length" and the "width" ;

→ The length is: "5x" ;

5x = 5(7) = " 35 in " ;
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→ The width is: "4x" ;

4x = 4(7) = "28 in."
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Let us check our answer:

→ A = L * w ;

→ 980 in² = ? 35 in. * 28 in. ?? ;

Using a calculator: "35 * 28 = 980" . Yes! ;
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{ Also note: " in * in = in² " ? Yes! } .
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3 0

2 years ago

Write as a fraction.

lesantik [10]

Answer:

the answer is 5/8

Step-by-step explanation:

8 0

3 years ago

Read 2 more answers

Consider a population consisting of the number of teachers per college at small 2-year colleges. Suppose that the number of teac

agasfer [191]

Answer:

a) $\frac{8}{9}$ =0.89

b) 0.8413

Step-by-step explanation:

we know that

$P(║ x -\mu║ \leq k\sigma) \geq 1 -\frac{1}{k^2}$

$so, \mu = 150, \sigma = 20$

$k = \frac{210 - 150}{20} =\frac{150 - 90}{20} = 3$

$P(║ x -150 ║ \leq 3\times 20) \geq 1 -\frac{1}{3^2} = \frac{8}{9}$

x - N(150, 20^2)

$P(X \leq 170) = 0.8413447$

check

$P norm = \frac{170 - 150}{20}= 0.8413447$

8 0

3 years ago

Sarah's mom takes the parkway to work it takes her 30 minutes to travel from mile marker 88th where she answers to her exit at m

pentagon [3]

121- 88 = 33 miles traversed in 30 minutes.

d = r*t
33 = r* (.5 hr)

Solve for r. Average speed will be in miles per hour. <span>
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7 0

3 years ago