Fill in the blank space for the given series with the correct alternative.
$840, 168, 42, 14, 7, (...)$

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

questions.

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

$'78'$ is to $'P?6'$ and $'?N'$ is to $'T32'$ in the same way as $2 E'$ is to $\ldots \ldots \ldots . . .$ in the arrangement.

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

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

If all the symbols are removed from the above arrangement, which element will be third to the left of thirteenth from the left?

Following questions are based on the five three-digit numbers given.
$513, 248, 371, 634, 167$
If the positions of the first and the second digits in each of these numbers are interchanged,which of the following will be the lowest number among them?

Choose the correct alternative to complete the series: $...bcdbc...dcabd....bcdbc....dc....bd$

Find out the wrong term from the given series.
$6, 13, 18, 25, 30, 37, 40$