Question

the sum of the first and third term of a GP is 40 while the fourth and sixth term are in the ratio 1:4 find;common ratio and fifth term

Answer 1

Answer:

4th term is 1 out of (4+1) = 1/5 sixth term is 4/5

1/5 x r x r = 4/5

r^2 = 4 r =2

1st and third terms x + x * r * r = 40

x + 4x = 40

x = 8 = first term

5th term 8 r^4 = 8 * 16 = 128