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3 years ago

3.

Mathematics

2 answers:

zheka24 [161]3 years ago

6 0

Answer:

Step-by-step explanation:

Sn = (n/2)(a1 + a1 + d(n-1)), where S = sum, a1 = first term, n = number of terms, d = common difference

400 = (n/2)(1 + 1 + 2(n - 1))

400 = (n/2)(2 + 2n - 2)

400 = (n/2)(2n

400 = n2

20 = n

Twenty numbers are in the set.

Lesechka [4]3 years ago

3 0

Answer:

Step-by-step explanation:

You might be interested in

Lucia uses 3 ounces of pasta to make 3/4 serving of pasta, How many ounces of pasta are there per serving? How many ounces of pa

natka813 [3]

Answer:

1. 4 ounces of pasta per serving.

2. 20 ounces for 5 servings.

Step-by-step explanation:

3 ounces of pasta makes 3/4 servings of pasta.

We want to get find out how many ounces of pasta needed to make 1 serving of pasta, in other words 4/4 servings of pasta.

To get 3/4 to 4/4, we need to times it by 4/3, since 3/4 * 4/3 = 12/12 = 4/4 = 1.

So to get the ounces of pasta, we need to times 3 by 4/3.

3 * 4/3 = 3/1 * 4/3 = 12/3 = 4 ounces.

There we see that there are 4 ounces of pasta in a serving.

Now that we know that there are 4 ounces of pasta in a serving, we simply multiply to get the amount of ounces of pasta in 5 servings.

We can say that the amount of pasta is directly proportional to the amount of servings.

Direct proportion is the relationship between two variables when their ratio is equal to a constant value.

If there are 4 ounces of pasta in a serving, the amount of servings is multiplied by 5, and since the amount of pasta is directly proportional to the amount of servings, we multiply the ounces of pasta by 5.

4 * 5 = 20.

Here we see that there are 20 ounces of pasta in 5 servings.

Hope this helps.

7 0

3 years ago

Maureen earned some money doing odd jobs last summer and put it in a savings account that earns 9% interest compounded quarterly

ivolga24 [154]

Answer:

Maureen earned $123.19 doing odd jobs

Step-by-step explanation:

The compound interest formula is given by:

$A(t) = P(1 + \frac{r}{n})^{nt}$

Where A(t) is the amount of money after t years, P is the principal(the initial sum of money), r is the interest rate(as a decimal value), n is the number of times that interest is compounded per unit year and t is the time in years for which the money is invested or borrowed.

In this question:

Compounded quarterly means that $n = 4$

10 years, so $t = 10$

9% interest, so $r = 0.09$

There is $300.00 in the account, which means that $A = 300$

How much did Maureen earn doing odd jobs?

This is P.

$A(t) = P(1 + \frac{r}{n})^{nt}$

$300 = P(1 + \frac{0.09}{4})^{4*10}$

$(1.0225)^{40}P = 300$

$P = \frac{300}{(1.0225)^{40}}$

$P = 123.19$

Maureen earned $123.19 doing odd jobs

5 0

3 years ago

Mr Wallace sells appliances in receives a weekly salary of $275 plus a 3% Commission on all of his self last week is sells total

Greeley [361]

Answer:

The total earning of Mr Wallace for the week is $310.37

Step-by-step explanation:

Given as :

The fixed weekly salary of Mr Wallace = $275

And The commission of 3% on his total sell

Last week Mr Wallace total sells amount= $1179

I.e 3% of total sells amount = 3% of $1179 = .03 × $1179 = $35.37

∴The total earning = $275 + $35.37 = $310.37

Hence The total earning of Mr Wallace for the week is $310.37 Answer

8 0

3 years ago

If 10% of my money is $15, then what is 40% of my money?

saul85 [17]

$\begin{array}{ccll} \%&amount\\ \cline{1-2} 10&15\\ 40&x \end{array}\implies \cfrac{10}{40}=\cfrac{15}{x}\implies \cfrac{1}{4}=\cfrac{15}{x}\implies x=60$

4 0

2 years ago

Read 2 more answers

(-1,19) and (3, 35)

natka813 [3]

Answer:

$\displaystyle \boxed{-4x + y = 23}$

Step-by-step explanation:

First, find the rate of change [slope]:

$\displaystyle \frac{-y_1 + y_2}{-x_1 + x_2}$

$\displaystyle \frac{-19 + 35}{1 + 3} = \frac{16}{4} = 4$

Then, plug these coordinates into the Slope-Intercept Formula instead of the Point-Slope Formula because you get it done much swiftly. It does not matter which ordered pair you choose:

35 = 4[3] + b

$\displaystyle 23 = b \\ \\ y = 4x + 23$

Then convert to Standard Form:

y = 4x + 23

- 4x - 4x

__________

$\displaystyle -4x + y = 23$

_______________________________________________

19 = 4[−1] + b

−4

$\displaystyle 23 = b \\ \\ y = 4x + 23$

Then convert to Standard Form:

y = 4x + 23

- 4x - 4x

__________

$\displaystyle -4x + y = 23$

** You see? I told you it did not matter which ordered pair you choose because you will ALWAYS get the exact same result.

I am joyous to assist you anytime.

4 0

3 years ago