PLEASE HELP ME 10 POINTS!!!!!

220 students were asked if they liked chocolate or vanilla ice cream. 140 said they liked chocolate and 120 said they liked vani

Flura [38]

Answer: D. 40

Step-by-step explanation:

Given: Number of students liked vanilla or chocolate ice cream = $n(V\cup C)=220$

Number of students liked chocolate = $n(C)=140$

Number of students liked vanilla= $n(V)=120$

Now, Number of students liked vanilla and chocolate ice cream is given by :-

$n(V\cap C)=n(C)+n(V)-n(V\cup C)\\\\\Rightarrown(V\cap C)=140+120-220\\\\\Rightarrown(V\cap C)=260-220\\\\\Rightarrown(V\cap C)=40$

Number of students liked vanilla and chocolate ice cream= 40

6 0

4 years ago

An oil refinery is located on the north bank of a straight river that is 2 km wide. A pipeline is to be constructed from the ref

hichkok12 [17]

Answer:

P is exactly 3km east from the oil refinery.

Step-by-step explanation:

Let's d be the distance in km from the oil refinery to point P. So the horizontal distance from P to the storage is 3 - d and the vertical distance is 2. Hence the diagonal distance is:

$\sqrt{(3 - d)^2 + 2^2} = \sqrt{(3 - d)^2 + 4}$

So the cost of laying pipe under water with this distance is

$800000\sqrt{(3 - d)^2 + 4}$

And the cost of laying pipe over land from the refinery to point P is 400000d. Hence the total cost:

$800000\sqrt{(3 - d)^2 + 4} + 400000d$

We can find the minimum value of this by taking the 1st derivative and set it to 0

$800000\frac{2*0.5*(3-d)(-1)}{\sqrt{(3 - d)^2 + 4}} + 400000 = 0$

We can move the first term over to the right hand side and divide both sides by 400000

$1 = 2\frac{3 - d}{\sqrt{(3 - d)^2 + 4}}$

$\sqrt{(3 - d)^2 + 4} = 6 - 2d$

From here we can square up both sides

$(3 - d)^2 + 4 = (6 - 2d)^2$

$9 - 6d + d^2 + 4 = 36 - 24d + 4d^2$

$3d^2-18d+27 = 0$

$d^2 - 6d + 9 = 0$

$(d - 3)^2 = 0$

$d -3 = 0$

d = 3

So the cost of pipeline is minimum when P is exactly 3km east from the oil refinery.

3 0

3 years ago

#2 Q is between P and R. Find PR. 6x + 4 3x 3x tc P R Q 14x - 6 6-

otez555 [7]

Answer:

PR=22

Step-by-step explanation:

3x+6x+4=14x-6

9x+4=14x-6

10=5x

x=2

Plug in

3(2)

6

6(2)+4

12+4

16

16+6

22

So the bottom should equal 22

14(2)-6

28-6

22

Hope this helps

Brainliest would be appreciated

8 0

3 years ago

Sam is riding his bicycle. He rides for 11.2 kilometers at a speed of 7 kilometers per hour. For how many hours does he ride?

Airida [17]

Answer:

1.6 hours

Step-by-step explanation:

you divide 11.2 by 7

hope this is correct

6 0

3 years ago

Read 2 more answers

A music website tracked the number of new users per day over 1 week. The number of new users for each day of the 7 days was 38,

enyata [817]

Part a)

MAD = median of absolute deviations

MAD = median of the set formed by : |each value - Median|

Then, first you have to find the median of the original set

The original set is (38, 43, 45, 50, 51, 56, 67)

The median is the value of the middle (when the set is sorte). This is 50.

Now calculate the absolute deviation of each data from the median of the data.

1) |38 - 50| = 12
2) |43 - 50| = 7
3) |45 - 50| = 5
4) |50 - 50| = 0
5) |51 - 50| = 1
6) |56 - 50| = 6
7) |67 - 50| = 17

Now arrange the asolute deviations in order

(0, 1, 5, 6, 7, 12, 17)

The median is the value of the middle: 6.

Then the MAD is 6.

Part b) MAD represents the median of the of the absolute deviations from the median of the data.

3 0

3 years ago