Arithmetic

Question 1

What are real numbers?

Answer 1

All rational and irrational (square root, pi) numbers

Question 2

What is an interval?

Answer 2

Set of all real numbers between two numbers.

ex) 2 < x < 3
interval is between 2 and 3

Question 3

Sum of exterior angles of any figure is always equal to what?

Answer 3

360 degrees

Question 4

combination and permutations formula: when order of choices matters

Answer 4

(n-r)!

Question 5

combination and permutations formula: when order doesn’t matter

Answer 5

r!(n-r)!

Question 6

combination and permutations formula: If there are a number of successive choices to make and the choices are independent of each other

Answer 6

Product of number of choices at each stage.
Ex) How many ways to arrange these letters, STOP.
4x3x2x1=24

Question 7

If a > 1 how does a^2 relate to a?

Answer 7

a^2 > a

Question 8

If 0 < b < 1, then in what way does b^2 relate to b

Answer 8

b^2 < b

Question 9

Divisibility rules. Is number divisible by 3?

Answer 9

Yes, if sum of digits divides by 3

Question 10

Is number divisible by 4?

Answer 10

Yes, if last 2 digits divide by 4

Question 11

Is number divisible by 5?

Answer 11

Yes, if last digit is a 0 or a 5.

Question 12

Is number divisible by 6?

Answer 12

Yes, if it’s divisisible by 2 and 3.

Question 13

Is number divisible by 8?

Answer 13

Yes if number formed by last 3 digits is divisible by 8.

Question 14

Is number divisible by 9?

Answer 14

Yes, if sum of digits is divisible by 9

Question 15

How to set up percent problems

Answer 15

percent “is” number
———— = ———–
100 “of” number