Refer to the following letter and symbol series and answer the question. Counting is to be done from left to right only. (Left) O N & # K € S * P # £ * G I & * @ I A * @ © (Right) How many such letters are there each of which is immediately preceded by a letter and also immediately followed by a symbol?

Refer to the following number series and answer the question. (Left) 2 8 9 3 5 7 6 3 1 4 8 9 3 5 1 5 6 2 1 4 7 5 2 3 8 2 9 (Right) How many such odd digits are there, each of which is immediately preceded by an odd digit and also immediately followed by an even digit?

Which of the following letter-number clusters will replace the question mark (?) in the given series to make it logically complete? CAR78, GEV86, KIZ94, OMD102, ?