Question

The first term of a certain sequence is 6 and the

second term is 12. The third term and each
term thereafter is found by taking the average
of the two terms preceding it. What is the value
of the first term in the sequence that is not an
integer?

Answer 1

`(21)/(2)`

Explanation:

Given

a₁ = 6

a₂ = 12 , then

a₃ =
`(6+12)/(2)` =
`(18)/(2)` = 9 ← an integer

a₄ =
`(12+9)/(2)` =
`(21)/(2)` ← not an integer

Thus the fourth term is not an integer