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jok3333 [9.3K]
3 years ago
10

Rob is saving to buy a new MP3 player. For every $13 he earns babysitting, he saves $9. On Saturday, Rob earned $78 babysitting.

How much money did he save?
Mathematics
1 answer:
stealth61 [152]3 years ago
7 0

Answer:

54$

Step-by-step explanation:

We know that for each 13$ Rob earns babysitting, he saves 9$. Thus, we can separate the money he earns into groups of 13, and for each group of 13, we can add 9$ to his savings.

Assume that Rob has 78$ lying on a table. He grabs 13 of them, leaving 65, and puts 9$ to the side for savings. He does this 5 more times (as 65 divided by 13 is 5, so Rob would make 5 groups of 13 out of his 65$ that is left), meaning that he now has 5+1  (the original group) = 6 groups of 9. 9*6=54, so he saves 54$. Please let me know if you have any further questions!

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What is the length of segment AB? (4 points)
Sveta_85 [38]

Answer:

10 units

Step-by-step explanation:

\sqrt{(0-6)^{2} +(10-2)^{2} }\\\\\sqrt{(-6)^{2}+(8)^{2} } \\\\\sqrt{36+64}\\\\\sqrt{100}\\\\10

3 0
2 years ago
There are 22 rows of seats on a concert hall: 23 seats are in the 1st row, 27 seats on the 2nd row, 31 seats on the 3rd row, and
JulijaS [17]
We can model this situation with an arithmetic series.
we have to find the number of all the seats, so we need to sum up the number of seats in all of the 22 rows.

1st row: 23
2nd row: 27
3rd row: 31
Notice how we are adding 4 each time.

So we have an arithmetic series with a first term of 23 and a common difference of 4.

We need to find the total number of seats. To do this, we use the formula for the sum of an arithmetic series (first n terms):

Sₙ = (n/2)(t₁ + tₙ)

where n is the term numbers, t₁ is the first term, tₙ is the nth term

We want to sum up to 22 terms, so we need to find the 22nd term

Formula for general term of an arithmetic sequence:

tₙ = t₁ + (n-1)d,

where t1 is the first term, n is the term number, d is the common difference. Since first term is 23 and common difference is 4, the general term for this situation is

tₙ = 23 + (n-1)(4)

The 22nd term, which is the 22nd row, is

t₂₂ = 23 + (22-1)(4) = 107

There are 107 seats in the 22nd row.

So we use the sum formula to find the total number of seats:

S₂₂ = (22/2)(23 + 107) = 1430 seats

Total of 1430 seats.
If all the seats are taken, then the total sale profit is

1430 * $29.99 = $42885.70
4 0
3 years ago
What is the answer when u covert the fraction 9/20 to decimal
ozzi
\dfrac{9}{20}=\dfrac{45}{100}=0.45
7 0
3 years ago
SHOW WORK
mote1985 [20]
1). The answer is 86. .29n =24.94
In order to obtain this you need to divide both sides by .29

2) The answer is 25%
35/140 x 100% =25%

3) The answer is $70
So if 100% of 40 is 40 and 75% of 40 is 30 than you need to add 40 + 30 which equals 70.

Hope this helps :)
4 0
2 years ago
A fighter tank targets an enemy helicopter flying at an altitude of 1250 ft. If the ground
madam [21]

By using trigonometric relations, we will see that the angle of elevation must be 55°.

<h3>How to find the angle of elevation?</h3>

We can see this as a right triangle, where one cathetus measures 1250ft (altitude) and the other cathetus measures 875ft.

The angle of elevation is the angle such that the adjacent cathetus is the one measuring 875ft.

Then we can use the relation:

tan(a) = (opposite cathetus)/(adjacent cathetus)

tan(a) = 1250ft/875ft

To find the angle of elevation, we can use the inverse tangent function:

a = Atan(1250ft/875ft) = 55°

The angle of elevation must be 55 degrees.

If you want to learn more about right triangles:

brainly.com/question/2217700

#SPJ1

7 0
1 year ago
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