Arithmetic sequence

1/3, 1, 1/6, 2

is this an arithmetic sequence? i have seen it in a grade 10 book, thanks

Arrange the numbers in increasing value: 1/6, 1/3, 1, 2. For a sequence to be arithmetic, the difference of two consecutive terms (any term - preceding term) must be equal. Let us check:

(a) 1/3 - 1/6 = 1/6
(b) 1 - 1/3 = 2/3
(c) 2 - 1 = 1

Since the difference of two adjacent terms are not equal, the given terms do not form into arithmetic sequence.