On the board, your teacher shows an example of finding the range. One of the numbers is erased, leaving what is shown.

Which of the following could NOT be true?
18, 30, 26, 12, 22
Range = 18

A. The missing number is 11
B. The missing number is 20
C. The missing number is 25
D. The missing number is 30

I think answer is B or C or D

Step-by-step explanation:

sites:

, and

for

step-by-step explanation:

we can analyze the pattern at which the terms increase. let us denote , , , so that we can call

note the following:

the pattern: to get the next term value, we just add the next term number (e.g. 1st, 2nd, to the previous term value (term values are the given numbers in the question, 1, 3, 6, 10, 15,

from , to get to , we add

from , to get to , we add

etc.

we need to form a recursive formula, a formula that has the next term as a function of the previous term. so a possible recursive formula can be

, and for