1.
A 9 digit number in which zero does not appear and no digits are repeated has the following properties: The number comprising the left most two digits is divisible by 2, that comprising the left most three digits is divisible by 3, and so on

2.
The remainder obtained when any prime number greater than 6 is divided by 6 must be :

3.
The smallest number which must be subtracted from 8112 to make it exactly divisible by 99 is :

4.
If the sum of two numbers is 14 and their difference is 10, find the product of these two numbers.

5.
The greatest number by which the product of three consecutive multiples of 3 is always divisible is :