Probability Terms
An event that has a 100% chance of occurring
Certain
What is the probability of getting an even number when rolling a dice?
1, 2, 3, 4, 5, 6
3 even and 3 odd numbers
Probability = 3/6 = 1/2
5 less than a number
x - 5
Solve for x:
x + 9 = 15
x + 9 = 15
-9 -9
x = 6
If x = 2, find 2x + 3
2x + 3
= 2 (2) + 3
= 4 + 3
= 7
What are the possible outcomes when you flip a coin?
Heads or Tails
The probability of it raining today is 0.56.
What is the probability of it not raining today?
1 - 0.56
= 0.44
10 more than sum of a and b
a + b + 10
Solve for x:
3x - 11 = 10
3x - 11 = 10
+11 +11
3x = 21
÷3 ÷3
x = 7
State the like terms:
2a , 3a2 , 5ab , -ac , 7ba, 2b , -ab , 4ab2
5ab , 7ab and -ab
I have 10 red and 15 blue marbles. I pick a marble at random.
Complete the statement:
It is __________________ to get a blue than a red marble.
more likely
I spin an 8-sided spinner which is numbered 1, 3, 3, 4, 4, 4, 6, 7.
What is the probability of getting an odd number or 6?
1, 3, 3, 7 or 6
5 out of 8
Probability = 5/8
The perimeter of a square with side length of (x + 3) cm
4x + 12
Solve for x:
3 (2x - 7) = 33
3 (2x - 7) = 33
6x - 21 = 33
+21 +21
6x = 54
÷6 ÷6
x = 9
What is the name given to the term with no variables?
Constant
I have 6 squares, 6 triangles and 5 circles.
I remove a shape at random and set it aside.
If the first shape I take is a square, the probability that the next shape is also a square is as __________________ as a circle.
equally likely
What is the probability of picking the letter I from the word:
MOUNTBATTEN ?
4 Is from a total of 11 letters
Probability = 4/11
James is 8 years older than Bill and 7 years younger than Kate. Let Bill be x years old.
Find an expression for the sum of their ages.
James = x + 8
Bill = x
Kate = (x + 8) + 7 = x + 15
Sum = x + 8 + x + x + 15
= 3x + 23
Solve for x:
4 (1 - 2x) - 7 (2x + 5) = 13
4 - 8x - 14x - 35 = 13
-22x - 31 = 13
+31 +31
-22x = 44
÷-22 ÷-22
x = -2
Given that a = 2, b = 10 and c = 4, find the value of:
7a2 - 4b + 8 (2c - b)
7 (2 x 2) - 4 (10) + 8 (2x4 - 10)
= 28 - 40 - 16
= -28
Adam, Ben and Camille sit in a row of chairs, next to each other. List all the possible arrangements in which the 3 friends can sit.
6 possible arrangements:
ABC, ACB
BAC, BCA
CAB , CBA
I roll a dice 30 times.
How many times can I expect to get a number greater than 4?
Greater than 4 -> 5 or 6
Probability = 2/6 = 1/3
No. of times = 1/3 of 30 = 10
Two teachers take their 45 students on a field trip.
An adult ticket is $5 more than a child's ticket.
Find the cost of tickets for the whole group of teachers and students.
Child ticket = $x
Adult ticket = $ (x + 5)
Total cost
= 2 (x + 5) + 45 (x)
= 2x + 10 + 45x
= 47x + 10
I buy x books at $5 each and 2 more novels than books at $8 each.
The total cost was $94.
How many novels did I buy?
5x + 8 (x + 2) = 94
5x + 8x + 16 = 94
13x + 16 = 94
-16 - 16
13 = 78
÷13. ÷13
x = 6
The sum of 3 consecutive odd integers is 141.
Find the 3 integers.
Let the 3 integers be: x , x + 2, x + 4
x + x + 2 + x + 4 = 141
3x + 6 = 141
-6 -6
3x = 135
÷3 ÷3
x = 45
The 3 numbers are 45, 47 and 49