# If the fifth and sixth terms of a geometric sequence are 8 and 16, respectively, then what is the first term?

##### 1 Answer

Dec 3, 2016

Since these are consecutive terms, we can use the formula

#r = t_n/t_(n - 1)#

#r= 16/8#

#r = 2#

We now can solve for

Let's use

#16 = a xx 2^(6 - 1)#

#16 = a xx 2^5#

#16 = 32a#

#a = 16/32#

#a = 1/2#

Hopefully this helps!