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Example Questions
Example Question #3 : How To Find Range
The following is a list of the amount of students in each of five 3rd grad classrooms:
23, 27, 19, 31, 33. What is the range of the number of students in each classroom?
The range is the highest minus the lowest value in a given data set contains. Thus the low end of the range is the low number, or 19 students, and the high end of the range is the high number, or 33.
Subtracting the lowest value from the highest we get,
.
Therefore the range of the data set is .
Example Question #1 : How To Find Range
Find the range of the following set of numbers.
To find range, simply subtract the smallest number from the largest number. Thus,
Example Question #2 : How To Find Range
Find the range of the following set of numbers:
To find the range, simply take the difference of the smallest and largest numbers.
The largest number is, and the smallest number is .
Thus,
.
Example Question #3 : How To Find Range
Find the range of the following set of numbers:
To find range, simply subract the smallest number from the largest. Thus,
Example Question #1 : How To Find The Probability Of An Outcome
If two regular six-sided dice are rolled at the same time, what is the probability that the sum of the their numbers will be prime?
5/12
1/2
7/18
1/4
5/12
There number of possible outcomes is equal to six times six, or thirty-six. The sum of the two dice must be either 2, 3, 5, 7, or 11. There are 15 out of the 36 outcomes that would result in a sum that is a prime number:
[1,1], [1,2], [1,4], [1,6], [2,1], [2,3], [2,5], [3,2], [3,4], [4,1], [4,3], [5,2], [5,6], [6,1], [6,5]
Example Question #1 : Probability
Maria is planning the seating for the head table at a college gala. There are eight speakers that will be seated along one side of the table. Richard wants to sit beside Hang, and Maria knows that Thomas and Lily should not be seated together. In how many ways can Maria make up the seating plan?
The simplest way to solve this is to find the number of seating arrangements in which Richard and Hang are seated together and then subtract those in which Thomas and Lily are also seated together. Consider Richard and Hang as a unit. This pair can be arranged with the other six speakers in 7P7 ways. For each of these ways, Hang could be either on Richard’s left or his right. Thus, there are 7P7 × 2 = 10 080 arrangements in which Richard and Hang are seated together. Now also consider Lily and Thomas as a unit. The two pairs can be arranged with the remaining four speakers in 6P6 ways, and the total number of arrangements with each of the pairs together is 6P6 × 2 × 2 = 2880.
Therefore, the number of seating arrangements in which Richard and Hang are adjacent but Thomas and Lily are not is 10 080 − 2880 = 7 200.
Example Question #1 : How To Find The Probability Of An Outcome
{10, 12, 24, 50, 60, 100, 260, 480, 606, 1000}
What is the probability that a number selected randomly from the set will be divisible by both 4 and 6?
1/10
2/5
3/10
1/2
3/5
2/5
First, find the numbers that in the set that are divisible by 4. 12, 24, 60, 100, 260, 480, and 1000 are all divisible by 4. Now find the numbers that are divisible by 6. 12, 24, 60, 480, 606 are all divisible by 6. The numbers that are divisible by both 4 and 6 are 12, 24, 60, and 480, or 4 total numbers from the set. So 4 out of the 10 numbers are divisible by 4 and 6. The probablility is 4/10, which reduces to 2/5. The correct answer is 2/5.
Example Question #2 : Probability
Jacob was 27 years old when his son Mike was born. Mike was 23 years old when his son Sam was born. Sam will celebrate his seventh birthday in 2014. What year was Jacob born?
2007
1987
1964
1984
1957
1957
If Sam will celebrate his seventh birthday in 2014, then he was born in 2007. So Mike was born 23 years before in 1984 and Jacob was born 27 years before that in 1957.
If you answered 1964, then you did not factor that Sam was 7 years old at the time of calculation.
If you answered 1984, then you found the year that Mike was born, not Jacob.
If you answered 2007, then you found the year that Sam was born, not Jacob.
If you answered 1987, then you just subtracted 27 years old from the day of the party in 2014.
Example Question #1 : Probability
What is the probability of choosing two consecutive red cards from a standard deck of cards, if replacement is not allowed?
51/100
61/204
17/25
25/102
23/25
25/102
Probability = what you want ÷ total number
A standard deck of playing cards has 52 cards, with 4 suits and 13 cards in each suit
Choosing two red cards = 26 * 25 = 650
Choosing two cards = 52 * 51 = 2652
So the probabiulity of choosing 2 red cards is 650/2652 = 25/102
If replacement is allowed, then the probability of choosing 2 red cards becomes 676/2704 = 1/4
Example Question #2 : How To Find The Probability Of An Outcome
If x percent of 300 is 120, what is 175% of x?
320
310
70
50
70
120 is 40% of 300, so x = 40.
175% of 40 is equal to 70.
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