All categories

2 years ago

anna is on a road trip. she uses 3/4 of a tank of gas every 9/2 hours. How many tanks of gas will anna use after 12 hours?

Mathematics

1 answer:

tatiyna2 years ago

7 0

Answer:

Step-by-step explanation:

This is a proportional question. If you learn how to keep things together, they are not only easy to do, they are mechanical: they are all done exactly the same way.

tanks of gas different tanks of gas

========== = ================

hours different hours.

initial tank of gas = 3/4 tank

initial hours = 9/2 = 4.5 hours

final tanks of gas = X

final time = 12 hours.

Solution

3/4 x

==== = ==============

4.5 12

Cross multiply

4.5x = 12*3/4 Combine the right

4.5x = 36/4 Simplify

4.5x = 9 Divide both sides by 4.5

x = 9/4.5

x = 2

So she will need 2 tankfuls.

You might be interested in

A certain standardized test's math scores have a bell-shaped distribution with a mean of 530 and a standard deviation of 119. Co

kumpel [21]

Answer:

a) 68.2%

b) 31.8%

c) 2.3%

Step-by-step explanation:

We are given the following information in the question:

Mean, μ = 530

Standard Deviation, σ = 119

We are given that the distribution of math scores is a bell shaped distribution that is a normal distribution.

Formula:

$z_{score} = \displaystyle\frac{x-\mu}{\sigma}$

a) P(test scores is between 411 and 649)

$P(411 \leq x \leq 649)\\\\= P(\displaystyle\frac{411 - 530}{119} \leq z \leq \displaystyle\frac{649-530}{119})\\\\= P(-1 \leq z \leq 1)\\\\= P(z \leq 1) - P(z < -1)\\= 0.841 - 0.159 = 0.682 = 68.2\%$

b) P(scores is less than 411 or greater than 649)

$P(x < 411 < x, x > 649)\\=1 = P(411 \leq x \leq 649)\\=1 - 0.682\\=0.318 = 31.8\%$

c) P(score greater than 768)

P(x > 768)

$P( x > 768) = P( z > \displaystyle\frac{768 - 530}{119}) = P(z > 2)$

$= 1 - P(z \leq 2)$

Calculation the value from standard normal z table, we have,

$P(x > 768) = 1 -0.977 = 0.023 = 2.3\%$

5 0

3 years ago

I’m having trouble understanding how to solve this someone please help ASAP thank you!

vladimir2022 [97]

Answer:

Answer is 71.95°

Step-by-step explanation:

Cosine formula is

a^2=b^2+c^2-2bc(cosA)

cos A =b^2+c^2-a^2/2bc

if a= 119,b=94,c=173

cos A=94^2+173^2-119^2/2(94*173)

=8836+29,929-14,161/2(16,262)

=38765-14,161/32,524

=24604/32,524

=0.7564

cos A=0.7564

cos^-1=40.85°.that's for angle A.

Using the same formula

B=31.1°

C=180-(40.85+31.1)

C=180-71.95

C=108.05

Since angle on a straight line is 180

therefore x is 71.95

Also the sum of angles A and B

3 0

1 year ago

Find the measure of arc EC.

miss Akunina [59]

Answer:

Step-by-step explanation:

$7x = (90 + 5x) \times \frac{1}{2}$

$7x = {2.5x} + 45$

$4.5x = 45$

$x = 10$

Plug 10 in for x.

$5(10) = 50$

8 0

2 years ago

we believe that 42% of freshmen do not visit their counselors regularly. For this year, you would like to obtain a new sample to

Maksim231197 [3]

Answer:

A sample of 1077 is required.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $1-\alpha$ , we have the following confidence interval of proportions.