Question

Identify the 33rd term of the arithmetic sequence 9, 7 1/2, 6.

Answer 1

The formula of arithmetic sequence is expressed in the following manner:
an = a1 + d*(n-1) where d is the difference and n is an integer.
substituting, 
7  = 9 + d*(2-1)
d= -1.5

hence, 
a33 = 9 - 1.5*(33-1)
a33 = -39