Prime Numbes & Factors

     1) Which of these numbers are prime ?

                    21  23  25  27  29

     2) What are the next two prime numbers after 3O ?

     3) Express the following numbers as prime factors:

           1.  48     4.  60     7.  70     10.  100 
           2.  99     5.  180    8.  96     
           3.  52     6.  24     9.  64     

     4) From the numbers 8, 12, 16, 19, 20

           a)  Which number is a prime number?
           b)  Which number is a square number?
           c)  Which is a multiple of 5?
           d)  Which is a factor of 84?

     5) Which of these numbers are prime ?

             18, 19, 20, 23,25, 27

             Which are square numbers?

     6) Express 1728 in prime factors.