13 is 65% of what number?

The area of a recalangle that is 8 feet long and 4 feet wide is

Flura [38]

Answer:

C is the answer! You're welcome

7 0

2 years ago

Read 2 more answers

A room has eight switches, each of which controls a different light. Initially, exactly five of the lights are on. Three people

aivan3 [116]

Answer:

The probability that 3 lights are on after the third person exited the room is 39/128

Step-by-step explanation:

In order for 6 switches to be on at the end, we need exactly 2 people turning on a switch and the other one turning one off. There are 3 possibilities:

The first two persons turn the switch in and the last one turns it off
The first and last person turn the switch in and the middle one tunrns it off
The first person turns the switch off and the 2 remaining turn the switch in

Note that after turning off one switch one more switch will be available to be switched in and one less will be available to be switch off. The contrary happens when someone turns in a switch.

Lets calculate the probability for the first scenario. The probability for the first person to turn the switch in is 3/8, because there are 3 lights off. For the second person, there will be only 2 lights off, thus, the probability for him or her to turn the switch in is only 2/8, leaving only 1 light off and 7 on. The third person will have, as a consecuence, a probability of 7/8 to turn off one of the 7 switches. This gives us a probability of 3/8 * 2/8 * 7/8 = 21/256 for the first scenario.

For the second scenario we will have a probability of 3/8 for the first person, a probability of 6/8 for the second one (he has to turn a switch off this time), and a probability, again, of 3/8 for the third one, giving us a probability of 3/8*6/8*3/8 = 27/256 for the second scenario.

For the third scenario, the first person has to turn off the switch, and it has a probability of 5/8 of doing so. The second person will have 4 switches to turn on, so it has a probability of 4/8 = 1/2, and the third person will have one switch less, thus, a probability of 3/8 of turning a switch on. Therefore, the probability of the third scenario is 5/8*1/2*3/8 = 15/128 = 30/256

By summing all the three disjoint scenarios, the probability that six lights are on is 21/256+27/256+30/256 = 78/256 = 39/128.

8 0

2 years ago

How do you take notes in math? I am struggling on math and I don't know how to take notes in math. ASAP! Please! I know how to t

Delvig [45]

Answer:

Step-by-step explanation:

1) Calm down, your motivated and determined so you will do awesome!

2) write the date AND the chapter the notes are from

3) Write down EVERYTHING even the stuff your teacher says that you dont need to write down

4) use a highlighter or underline important info, your brain cant memorize everything!

5) draw pictures! math is all about visualization

6) if your teacher is teaching a new concept he/she will definetly give you some examples to write down, make up your own examples and solve them to go beyond

7) abbreviate, teachers talk pretty fast so you may struggle to get everything down, if you abbreviate writing will be faster, just dont forget to make a key for your abbreviations so that you dont forget!

8) ask for help!- the most effective tool in the shelf

9) go online and search up worksheets to do

10) write down in you notebook each step you need to take in order to get the answer.

11) Hope this helps! and good luck!

6 0

3 years ago

Which inequality represents all values of x for which the product below is<br> defined?<br><br> ixt1

sesenic [268]

Answer:

Step-by-step explanation:

i got band and theres nothing below

6 0

3 years ago

If you are given the following stem and leaf display and asked to construct a frequency distribution chart, what would be the wi

Nuetrik [128]

Answer:

Width of intervals: 8

Step-by-step explanation:

We first look at how data is represented in a stem-leaf diagram.

Any number of the left (before -) is the stem and all numbers on right (after -) are the leaves. Each combination of stem and leaf represents one number. For example: 1 - 332 represents: 13, 13, 12.

Our data is as follows:

13, 13, 12, 24, 25, 31, 31, 35, 37, 42, 43, 41, 52, 51, 51, 52

To calculate the width of the frequency distribution chart, we have the following formula:

$Class\ width = \frac{Range}{Number\ of\ classes}$

The range of any data set = Maximum value in the data set - Minimum value in the data set

Maximum value in this case as seen from the data is 52 and minimum is 12.

Range = 52 - 12 = 40

Since we had only 5 stems in the data, we shall use that as the number of classes required in the frequency distribution chart.

$Class\ width = \frac{40}{5} = 8$

Hence, the class width in this data set will be 8.

To make the intervals, we begin from the minimum value and add 8 to it. The intervals will be:

12 - 20

20 - 28

28 - 36

36 - 44

44 - 52

Observe, that all the values of the stem lie within each interval.

For example, there are 3 values for stem 1: 12, 13, 13 and each lie in the first interval 12 - 20.

Next, the values of stem 2 are 24 and 25. Each of these value lie in the second interval 20 - 28; and henceforth.

8 0

3 years ago

13 is 65% of what number?​

13 is 65% of what number?