Answer: The general term of 40,20,10,5,..., is an = 5. 2^(4-n)
Step-by-step explanation: 40,20,10,5, ..., are the terms of a geometric progression whose first term is a1 = 40 and its ratio is
R = 20/40 = 1/2 . Therefore, its general term is an:
an = a1 . R^(n-1)
an = 40 . (1/2)^(n-1)
an = 5 . 2^3][ 2^(1-n)]
an = 5 . 2^(4-n)
The general term for 40,20,10,5,..., is an = 5 . 2^(4-n)