Solve and graph the inequality - x/4

A coin bank that excepts only nickels and dimes contains $9.15. There are three more than twice as many nickels as there are dim

valentinak56 [21]

45 dimes and 93 nickels were in bank

<em><u>Solution:</u></em>

Let "n" be the number of nickels

Let "d" be the number of dimes

We know that,

value of 1 nickel = $ 0.05

value of 1 dime = $ 0.10

<em><u>Given that There are three more than twice as many nickels as there are dimes</u></em>

Number of nickels = 3 + 2(number of dimes)

n = 3 + 2d ---- eqn 1

<em><u>Also given that coin bank that excepts only nickels and dimes contains $9.15</u></em>

number of nickels x value of 1 nickel + number of dimes x value of 1 dime = 9.15

$n \times 0.05 + d \times 0.10 = 9.15$

0.05n + 0.10d = 9.15 ---- eqn 2

<em><u>Let us solve eqn 1 and eqn 2</u></em>

Substitute eqn 1 in eqn 2

0.05(3 + 2d) + 0.10d = 9.15

0.15 + 0.1d + 0.10d = 9.15

0.2d = 9

From eqn 1

n = 3 + 2(45)

n = 3 + 90 = 93

Thus 45 dimes and 93 nickels were in bank

3 0

3 years ago

Scores from an exam are normally distributed with a mean of 85 and a standard deviation of 5. Suppose 188 students take the exam

charle [14.2K]

The mean is $\mu=85$ and standard deviation is $\sigma=5$ . Then the variable $X\sim N(85,5)$ .

Use substitution $Z=\dfrac{X-\mu}{\sigma}=\dfrac{X-85}{5}$ , then the variable $Z\sim N(0,1)$ .

The probability $Pr(X>80)$ can be calculated in the following way:

for X=80, $Z=\dfrac{80-85}{5} =-1$ and $Pr(X>80)=Pr(Z>-1)$ . From the diagram $Pr(Z>-1)=0.34+0.34+0.135+0.025=0.84$ .

Conclusion: if 188 students take the exam, then 188·0.84=157.92 (157) would receive a score above 80

4 0

3 years ago

Read 2 more answers

How do you solve x^2-4X-12=0

Pepsi [2]

x² - 4x - 12 = 0

Factor the left side: (x + 2) · (x - 6) = 0

The equation is true if either factor is zero.

If (x + 2) = 0 then x = -2 .

If (x - 6) = 0 then x = 6 .

3 0

3 years ago

I AM IN A TEST AND I NEED THE ANSWER SOON!!! PLEASEE!!!<br><br> THANK YOU SO MUCH!!

mart [117]

Hello,

If Viviana has 2/5 of pasta to share with four friends, you should divide. First change 2/5 to a decimal, 0.4. Now divide 0.4 and 4.

Workspace:

2/5 = 0.4

4 / 0.4 -> 10

Workspace End

Correct Answer:

10

Hope this helps!!
Brainliest??

8 0

2 years ago

Which of the following represents the zeros of f(x) = 2x3 − 5x2 − 28x + 15?

likoan [24]

$\mathrm{Use\:the\:rational\:root\:theorem}$