Straight Lines ...

A Printer number the pages of a book starting with $$1$$ and used $$3193$$ digit in all. How many pages does the book have:

There is a defined relationship between the pair of figure on either side of : :. Identify the relationship of the given pair and find be the missing figure.

7, 11, 23, 51, 103 ?

Using all digits $$2,3,4,5,6$$ how many even number can be formed 

The number of permutations of letters of the word "PARALLAL" atken four at a time must be, 

655, 439, 314, 250, 223 ?

$$1+1.1!+2.2!+3.3!+...+n.n!$$ is equal to 

$$\sum _{ k=1 }^{ 10 }{ k.k! } =$$

The number of was dividing $$52$$ cards amongst four players equally, are 

The number of words which can be made out of the letters of the word $$'MOBILE'$$ when consonants always occupy odd places is _______.