Fill in the blank space for the given series with the correct alternative.
$21, 25, 33, 49, 81, (...)$

Choose the correct alternative answer

$a...cdaab...cc....daa...bbb....ccddd$

What will come in place of the question mark $(?)$ in the following alphabet series?
$XDH, \quad VGJ, \quad TJL, \quad RMN, \quad ?$

These questions are based on the following letter/number/symbol arrangement. Study it carefully and answer the questions that follow.

$5, D,H,E, \star, 7,9, \$ ,F,I ,6 ,R ,\% ,L ,1 ,A,J, 3, B, \# ,4 ,@ ,K,P ,8, U,M, 2$

What will come in place of the question marks $(?)$ in the following series based on the above arrangement?

$E,D,H ,9 ,\star, 7, I,\$,F, ?, ?, ?$

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

These questions are based on the following set of numbers.
$738, 495, 329, 653, 849$
If $1$ is subtracted from the last digit of each number and then the numbers are arranged in descending order,which number will be the first?