Question

A bag contains 30 lottery balls numbered 1-30 a ball is selected, not replaced,then another is drawn.find each probability

Answer 1

The probability of the first event with x possible outcomes is equal to x/30. Also, the probability of the second event with y possible outcomes is y/29.

(1) P of 2 digit number, 21/30
      P that the number is 4 is 1/29
Multiplying both probabilities will give us 7/290

(2) P that number is 19 is 1/30
      P that the number is multiple by 4 is 6/29
The answer is 1/145

(3) P that number is 24 is 1/30
      P that number is less than 15 is 14/29
The answer should be 7/435.

(4) P that number 1st number is perfect square is 5/30
   P that second number is perfect square is 4/29.
The answer is 2/87.