How many words can be made from the letters of the word $DELHI$,if $L$ comes in the middle in every word?

The number lock of a suitcase has $4$ wheels,each labelled with ten digits,i.e.,from $0$ to $9$. The lock opens with a sequence of four digits with no repeats. What is the probability of a person getting the right sequence to open the suitcase?

$P, Q, R$ and $S$ have to give lectures to an audience. The organiser can arrange the order of their presentation in ............. ways.

The number of $5$-digit numbers which are divisible by $4$,with digits from the set $\{1, 2, 3, 4, 5\}$ and the repetition of digits is allowed,is . . . . . .

$10$ men and $6$ women are to be seated in a row so that no two women sit together. The number of ways they can be seated is:

Total number of $6$-digit numbers in which only and all the five digits $1, 3, 5, 7,$ and $9$ appear,is: