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3 years ago

Please help will give reward!

Mathematics

1 answer:

Shalnov [3]3 years ago

7 0

Answer:

3/4

Step-by-step explanation:

2 problems consist 8 choices of answers.

the events for the correct answer are 2

and the events for incorrect answer are 6

so, the probability that she answered neither of the problems correctly = 6/8 = 3/4

You might be interested in

For the function f(x)=10(x+5)−9, find the value of f(3)

Sergio [31]

Answer:

f(3) = 71

Step-by-step explanation:

f(x) = 10(x + 5) − 9

f(3) = 10(3 + 5) - 9

f(3) = 10(8) - 9

f(3) = 80 - 9

f(3) = 71

3 0

3 years ago

Add an intersection the red light times normally distributed by the mean of three minutes and a standard deviation of .25 minute

Soloha48 [4]

95% of red lights last between 2.5 and 3.5 minutes.

<u>Step-by-step explanation:</u>

In this case,

The mean M is 3 and
The standard deviation SD is given as 0.25

Assume the bell shaped graph of normal distribution,

The center of the graph is mean which is 3 minutes.

We move one space to the right side of mean ⇒ M + SD

⇒ 3+0.25 = 3.25 minutes.

Again we move one more space to the right of mean ⇒ M + 2SD

⇒ 3 + (0.25×2) = 3.5 minutes.

Similarly,

Move one space to the left side of mean ⇒ M - SD

⇒ 3-0.25 = 2.75 minutes.

Again we move one more space to the left of mean ⇒ M - 2SD

⇒ 3 - (0.25×2) =2.5 minutes.

The questions asks to approximately what percent of red lights last between 2.5 and 3.5 minutes.

Notice 2.5 and 3.5 fall within 2 standard deviations, and that 95% of the data is within 2 standard deviations. (Refer to bell-shaped graph)

Therefore, the percent of red lights that last between 2.5 and 3.5 minutes is 95%

8 0

4 years ago

What is the value of x in the equation 40(x - 3) = 24x - 48?

pogonyaev

Answer:

x=10.5

Step-by-step explanation:

40x-120=24x-48

40x-168=24x

16x-168=0

16x=168

x=10.5

Have a great day!

6 0

3 years ago

At 12 noon,Leslie recorded the temperature as 56F.The temperature had increased by 8F from 10 A.M.The temperature at 8 A.M.Was 2

tigry1 [53]

I believe the answer is 50 degrees

7 0

3 years ago

While Brendan is vacationing with his family at the cabin, they take a motorboat on the river. The motorboat travels

taurus [48]

Part 1: The speed of the boat traveling downstream is $(18+w)$ miles per hr.

The speed of the boat traveling upstream is $(18-w)$ miles per hr.

Part 2: The speed of the current is 4 miles per hour.

Explanation:

Part (1): The motorboat travels 18 miles per hour in still.

Let w represents the speed of the current.

When the boat travels downstream, the speed of the current will get added to the speed of the boat.

Thus, the expression can be written as $(18+w)$ miles per hr

Hence, the speed of the boat traveling downstream is $(18+w)$ miles per hr.

When the boat travels upstream, the speed of the current will get subtracted to the speed of the boat.

Thus, the expression can be written as $(18-w)$ miles per hr.

Hence, the speed of the boat traveling upstream is $(18-w)$ miles per hr.

Part (2): The boat travels 49 miles upstream in the same time it takes to travel 77 miles downstream.

The distance formula is given by $distance $=$ speed $\times$ time$

Substituting, we have,

$49=(18-w)t\\49=18t-wt$ ---------------(1)

$77=(18+w)t\\77=18t+wt$ ---------------(2)

Solving using elimination method,

$49=18 t-w t\\77=18 t+w t\\-------\\126=36t$

Dividing both sides by 36, we have,

$t=3.5$

Substituting $t=3.5$ in $49=18 t-w t$ , we get,

$49=18(3.5)-w (3.5)\\$

$49=63-3.5w\\$

$-14=-3.5w\\$

$4=w$

Thus, the speed of the current is $w=4$ miles per hour.

5 0

4 years ago