Find the odd one out: 2, 4, 8, 16, 18 MCQ with Answer and Explanation

Explanation:
BEAT ER or BE ATER etc. Meaningful: BEAT and ER (not word), or BE and ATER no. Actually BEATER can be BEAT + ER no; or BE + ATER no. Common is 2: BEAT and ER is not, but perhaps AT and BEER no order preserved. Order preserved: possible BE, AT, ER. Three? But ER is not standard word in some. Standard answer often 2.

Explanation:
Differences are +5, +9, +13, +17, which increase by 4; next difference is +21, so 45+21=66.

Explanation:
The terms are squares descending: 10^2, 9^2, 8^2, 7^2, 6^2. Next term = 5^2 = 25.