Choose the correct alternative to complete the series: $aab....aa....bbb....aaa....bbba$

These questions are based on the following set of numbers.
$389, 476, 635, 847, 568$
If in all the numbers the first two digits are interchanged and then the numbers are arranged in ascending order,which number will be the second?

Choose the correct alternative to complete the series:
$a \_ \_ b a \_ \_ \_ b \_ \_ \_ \_ b \_ \_ \_ \_ a \_ \_ \_ \_ b$

To answer these questions study carefully the following arrangement of letters, digits and symbols.

$6,=,\$, C,E, 3,8 ,G,L,M, 7, \star, @ ,P,R, 4, \# ,N,T, 5, S,V$

If all the symbols in the arrangement are removed, then which of the following will be the $7^{th}$ to the left of the $13^{th}$ element from the left end?

In the series $7, 14, 28, \ldots$,what will be the $10^{th}$ term?

Find out the wrong term from the given series:
$8, 13, 21, 32, 47, 63, 83$