Twelve less than twice a number is 32. What is the number?

a neophyte is a beginner. on the first day of classes, 28,000 students arrived at the university campus. if three-sevenths were

navik [9.2K]

Answer:

16 ,000 students are not neophytes.

7 0

3 years ago

Read 2 more answers

In a box of 500 colored balls, 75 are black, 150 are green, 175 are red, 70 are white, and 30 are blue. what are the probabiliti

Oksanka [162]

If we want to select a ball of each colour we have to extract 175+150+75+70+1=471 balls

P=471/500 is the answer

4 0

3 years ago

the ratio of sallys height is 7:8. if the sum of their heights is 90 inches. how tall are sally and jack?

pickupchik [31]

Answer:

Sally is 42 in. tall, and Jack is 48 in. tall.

Step-by-step explanation:

There are some words missing in the problem.

Perhaps the problem was meant to read:

"The ratio of Sally's height to Jack's height is 7:8. If the sum of their heights is 90 inches, how tall are Sally and Jack?"

Solution:

The ratio of the heights is 7:8.

Sally could measure 7 inches and Jack 8 inches, but then when you add the heights, 7 in. + 8 in. = 15 in. which is not 90 inches.

If you multiply both numbers in a ratio by the same number, the new numbers are still in the same ratio.

Multiply 7 and 8 by 2. You get 14 and 16. Maybe Sally is 14 in. tall and Jack is 16 in. tall. Add the heights, 14 in. + 16 in. = 30 in. This is also not 90 in.

We can keep on guessing what number to multiply by 7 and 8 by so their sum is 90, but we can use algebra to write an equation and not have to go through many guesses.

There is a number, x, that when you multiply 7 and 8 by x, the sum of the products is 90. We don't know what x is, but we can write an equation and solve for x.

The numbers in the ratio are 7x and 8x.

7x and 8x are still in the ratio 7:8.

Now we add the numbers 7x and 8x and set the sum equal to 90. Then we solve for x.

7x + 8x = 90

15x = 90

x = 6

We get x = 6. Now we know we need to multiply both 7 and 8 by 6 to get the heights we need.

7 in. * 6 = 42 in.

8 in. * 6 = 48 in.

Check: 42 in. + 48 in. = 90 in.

Answer: Sally is 42 in. tall, and Jack is 48 in. tall.

7 0

2 years ago

Rex, Paulo, and Ben are standing on shore watching for dolphins. Paulo sees one surface directly in front of him about a hundred

Ksivusya [100]

1. $m\angle BAC=m\angle CAD,\ m\angle ACB=m\angle ADC=90^{\circ}$ , then $m\angle ABC=m\angle ACD$ and triangles ADC and ACB are similar by AAA theorem.

2. The ratio of the corresponding sides of similar triangles is constant, so

$\dfrac{AC}{AB}= \dfrac{AD}{AC}$ .

3. Knowing lengths you could state that $\dfrac{b}{c}= \dfrac{e}{b}$ .

4. This ratio is equivalent to $b^2=ce$ .

5. $m\angle ABC=m\angle CBD,\ m\angle ACB=m\angle CDB=90^{\circ}$ , then $m\angle BAC=m\angle BCD$ and triangles BDC and BCA are similar by AAA theorem.