-10x=-12x + 21 + 11
-10x= -12 + 32
-10x + 12x = 32
2x = 32
X = 32/2
Answer:
Standard deviation of the population is 2.4
Step-by-step explanation:
Finishing times of 6 participants in 200 meter dash has been given as 27, 28, 27, 25, 24, 31.
We have to calculate the standard deviation of the population formed by these timings.
Formula of standard deviation is
where 
= standard deviation
= mean of the data
n = number of scores in the sample
Mean of given data = 
= 
= 30
Now 
= 2.236 ≈ 2.24
Therefore, standard deviation of the given data is 2.24
1. The answer is 76.
If the group all together is only being charged once per ride, and the whole group is going twice, then you will double the cost of each ride:
4.50 x 2 = 9
4 x 2 = 8
3.50 x 2 = 7
In total, the rides will cost $24. So, if you're paying with a $100 bill, you will receive $76 in change.
2.2 The answer is 58.
You will do the same procedure as the first question, but this time multiply the costs by 3.
5.50 x 3 = 16.5
2 x 3 = 6
6.50 x 3 = 19.5
The total will be 42. Subtracted from 100, you will get 58.
3.3 The answer is 2.
If you have 15 dollars and the coaster costs 5.50, the first time you ride it you will have 9.50 left. The second time, you will have 4 dollars left, and then you will not be able to pay for a third time.
4.4 The answer is 23.25
If you add up all the correlating costs of the tickets (6.75 + 4.50 + 4.50 + 10.50 + 10.50), you will get 36.75. Then you must subtract that from 60, which will give you 23.25 dollars in change.
5.5 The answer is 54.75
You will do the same procedure here as you did above. Add the corresponding costs together (you're done after this part, because the question isn't asking for how much change you'll receive).
6.6 The answer is 7.
If the tickets cost $10.50 and you have $80, then you want to divide 80 by 10.50. You will get 7.6. Since you can't buy a sixth of a ticket, your answer will be 7.
7.7 The answer is to pay separately.
In this question, you will add all the costs together (except the day pass) and compare it to the cost of the day pass. Once you add all the costs together, you will get 17.50. This is cheaper than the day pass, which is 19.95.
are possible combinations .
<u>Step-by-step explanation:</u>
Here we have , A laptop lock has a 4 digit combination. Each character can be any digit between 0-7. The only restriction is that all 4 characters cannot be the same (e.g. 0000, 1111, 2222,... etc.). We need to find How many combinations are possible .Let's find out:
The first digit has 8 choices (can be all of them), the second digit also has 8 choices. The third and fourth digits also have 8 choices.
Multiply them together you get:
⇒ 
⇒ 
possible combinations.
But since all 4 characters cannot be the same, we subtract 8 from 4096 (there are 8 combinations which the 4 characters are the same: 1111, 2222, 3333, 4444, 5555, 6666, 7777, and 0000) and we get :
⇒ 
⇒
Therefore, are possible combinations .
