Consecutive Integers

Question 1

Counting integers: add 1 before you are done. How many integers are there from 6 to 10, inclusive?

Answer 1

5

Question 2

Counting integers in consecutive multiples: How many even integers between 12 and 24, inclusive?

Answer 2

The jumps are 2, so we do (Last - First) /2 +1

6

Question 3

Counting integers in evenly spaced sets: How many multiples of 7 are between 10 and 80? (note this does not say, “inclusive”)

Answer 3

(77 - 14)/7 = 9+1 = 10

Question 4

Evenly spaced sets: what’s the difference between the mean and median?

Answer 4

They are equal to each other. Example: 4, 8, 12, 16, 20: median and mean are 12

Question 5

Evenly spaced sets: what is teh mean in relation to the first and last number?

Answer 5

The meman is equal to the average of the first and last terms

Question 6

What is the sum of all integers from 20 to 50, inclusive?

Answer 6

The sum of an evenly spaced set = average * # of terms