Question

Which is the 9th term of the sequence which has a first term of 1 and has a common ratio of 1.5

A. 10.50

B. 42.51

C. 13.50

D. 25.63

Answer 1

Hey!
So what you can do is:
1 x 1.5 = 1.5(2nd term)
1.5 x 1.5=2.25(3rd term) x 1.5=3.375(4th term) x 1.5 = 5.0625(5th term)

5.0625 x 1.5=7.59375(6th term)x1.5= 11.390625

11.390625 x1.5= 17.0859375(8th term)x1.5= 25.62890625(9th term)

The answer is D!
Hope this helps!

Answer 2

The sequence would go:
1, 2.5, 4, 5.5, 7, 8.5, 10, 11.5, 13, 14.5

The 9th term should be 13