Tickets are numbered from 1 to 100. They are well shuffled and a ticket is drawn at random. What is the probability that the drawn ticket has: An even number, A number 5 or a multiple of 5, A number...

Tickets are numbered from 1 to 100. They are well shuffled and a ticket is drawn at random. What is the probability that the drawn ticket has:

1. 
   An even number,
   


2. 
   A number 5 or a multiple of 5,
   


3. 
   A number which is greater than 75,
   


4. 
   A number which is a square?