The third of geometric progression (G.P) is 10 and the sixth term is 80. Find the common ratio.
-
A.
2 -
B.
3 -
C.
4 -
D.
8
Correct Answer: Option A
Explanation
(T_{n} = ar^{n – 1}) ( Geometric Progression)
(T_{3} = ar^{3 – 1} = ar^{2} = 10 …. (1))
(T_{6} = ar^{6 – 1} = ar^{5} = 80 …..(2))
Divide (2) by (1)
(r^{5 – 2} = r^{3} = 8 )
(r = sqrt[3]{8} = 2)