Arithmetic

Question 1

How to calculate % increase or decrease?

Answer 1

Divide the increase by the original amount

E.g. If I price increases from 25 to 30 then the percent increase equals

5/25 = .2 = 20%

Question 2

Is the percent increase from 24 to 30 the same as the price decrease from 30 to 24?

Answer 2

No,

6/24 does not equal 6/30

Question 3

How do you tell if a multiplication of numbers is even?

Answer 3

If at least one factor of a product of integers is even, the product is even

Question 4

How to tell if the sum of integers is even?

Answer 4

If 2 integers are both even or both odd, sun is even.

Odd number of odd numbers = odd

Question 5

Can you shift a decimal point in long division?

Answer 5

Yes,

648.12/12.4 = 6481.2/124

Question 6

How many roots does a positive integer have?

Answer 6

2

Sq. Root of x and negative sq root of x

Question 7

How do you calculate a median

Answer 7

Middle term

If odd number, choose middle
If even number, average 2 middle terms

Question 8

What is a union?

Answer 8

All factors in both sets

Question 9

What is an intersection of 2 sets?

Answer 9

Only the like numbers in the two sets

Question 10

If you have n numbers, how many different orders can you put them in?

Answer 10

n!

Question 11

What is the equation for calculating the probability of choosing r objects from a larger group n?

Answer 11

nCr = n!/(r!)*(n-r)!

Question 12

What is the probability of A occurring if B occurred?

Answer 12

P = intersection of A and B / B

Aka if a dice used and A= 2,4,6 B=5,6 then P(AifB) is

[6]/[5,6] = 1/2

Question 13

If A and B are independent events, what is the probability of A and B occurring?

Answer 13

P(A)*P(B)

Question 14

If A and B are independent events, what is the probability of A or B occurring?

Answer 14

P(A)+P(B)-P(A)*P(B)

Question 15

9^x = ???

Answer 15

3^(2x) or 3(3^x)