All categories

9 months ago

Jennifer has 25 coins with a total value of $4.25. The coins are quarters and nickels. How many of each does she have?

Mathematics

1 answer:

kirill115 [55]9 months ago

8 0

Answer:

15 quarters, 10 nickels

Step-by-step explanation:

$q+n=25$

$0.25q+0.05n=4.25$

multiply the first equation by -0.25 and add the second equation to it

$-0.25q-0.25n=-6.25\\0.25q+0.05n=4.25$
________________
$-0.2n=-2$

$n=\frac{-2}{-0.2} =10$ has 10 nickels

$q=25-n=25-10=15$ has 15 quarters

10(.05) +15(0.25) = 0.5 + 3.75 = 4.25

Hope this helps

You might be interested in

Is three and five a factor pair of 15

Pie

Yes because 3*5 = 15

Factors multiply to get the product.

6 0

3 years ago

Read 2 more answers

The polynomial equation x^3+x^2=-9x-9 has complex roots +/-3i What is the other root? Use a graphing calculator and a system of

Ierofanga [76]

For this case what you can do is factorize the <span>polynomial equation</span>, which would be left like follows
x ^ 3 + x ^ 2 + 9x + 9 = 0
(x + 1) (x ^ 2 + 9) = 0
Resolving, we have that the missing root is
x = -1
Answer
x=-1

7 0

3 years ago

Explain how to use multiplication to find

Sindrei [870]

A fraction x/y is a ratio between two numbers x and y.

The ratio is preserved if both x and y are scaled up or down by the same number n.

This means you can obtain any fraction equivalent to x/y by multiplying both x and y by n, i.e. (n*x)/(n*y).

Then we have 1/4 = (2*1)/(2*4) = 2/8, for example.

5 0

3 years ago

To help consumers assess the risks they are taking, the Food and Drug Administration (FDA) publishes the amount of nicotine foun

QveST [7]

Answer:

We conclude that the mean nicotine content is less than 31.7 milligrams for this brand of cigarette.

Step-by-step explanation:

We are given the following in the question:

Population mean, μ = 31.7 milligrams

Sample mean, $\bar{x}$ = 28.5 milligrams

Sample size, n = 9

Alpha, α = 0.05

Sample standard deviation, s = 2.8 milligrams

First, we design the null and the alternate hypothesis

$H_{0}: \mu = 31.7\text{ milligrams}\\H_A: \mu < 31.7\text{ milligrams}$

We use One-tailed t test to perform this hypothesis.

Formula:

$t_{stat} = \displaystyle\frac{\bar{x} - \mu}{\frac{s}{\sqrt{n}} }$

Putting all the values, we have

$t_{stat} = \displaystyle\frac{28.5 - 31.7}{\frac{2.8}{\sqrt{9}} } = -3.429$

Now, $t_{critical} \text{ at 0.05 level of significance, 8 degree of freedom } = -1.860$

Since,

$t_{stat} < t_{critical}$

We fail to accept the null hypothesis and accept the alternate hypothesis. We conclude that the mean nicotine content is less than 31.7 milligrams for this brand of cigarette.

3 0

3 years ago

Write the number equal to 5 tens and 13 ones

zlopas [31]

63 5 tens=50
13 ones=10 and 3 leftover 50+13=63

4 0

3 years ago