Which one is odd from the others?

What is the minimum number of cars that could move in the following format? Two cars in front of a car, two cars behind a car and a car between two cars:

How many 9’s are there preceded by 3 in the given sequence? 

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In a certain code SISTER is 535301, UNCLE as 84670, and BOY as 129, how is SON coded?

If in a certain code EXIST is coded as ESIXT, how is PLUTO coded in the same language?

A doctor gives Rema five tablets asking her to take each one after half an hour. How long will she take to finish all the tablets?