Choose the correct alternative to complete the series: $ccbab...caa...bccc...a$

What will be the next term in the series: $BDF, CFI, DHL, ?$

Study carefully the following arrangement of letters, digits and symbols to answer these

questions.

$M, 7 , \# , 8, L ,P ,@ ,Q ,N ,\beta ,T ,Y ,3 ,2 ,= ,E ,\$ ,4 ,9 ,*, G ,H ,5$

If all the numbers are deleted from the arrangement, then which of the following will be fifth to the right of the $13^{th}$ element from the right end?

Which one of the following is the correct order of missing letters in the series given below?
$....sttt...tt...tts....$

The positions of how many digits in the number $7,3,5,4,6,1,2$ will remain unchanged after the digits within the number are rearranged in descending order from left to right?

Study the following arrangement carefully and answer the questions given below:

$7, R,E,T ,4 ,A ,9 ,\% ,D,F, 1, U, \# ,B ,@ ,8 ,H,I ,$©$, W,M, \star, 3,2 ,V ,\$ ,5 ,N,P,6, Q$

Four of the following five are alike in a certain way based on their position in the above arrangement and so form a group.

Which is the one that does not belong to the group?