How many terms are there in the G.P.
3, 6, 12, 24....... 384?
Answer & explanation
Correct answer: option 1
Tn = ar(n-1) , where n is the position of the term.
We want to find the nth term, so we substitute a = 3, and r = 2 into the formula:
384 = 3 × 2(n-1)
= 2(n-1) = 128
= 2(n-1) = 27
n – 1 = 7
n = 8