
There are two methods to find the G.C.D. of two or more numbers: (i) Method of Prime Factors (ii) Division Method
GCD using the Method of Prime FactorsExample: Find the G.C.D. of 48, 60.First, write the numbers given as the product of primes. 48 = 2 x 2 x 2 x 2 x 3. 60 = 2 x 2 x 3 x 5. We observe that 2, 2, and 3 are the common prime factors of 48 and 60. The product of the common prime factos is 2 x 2 x 3 = 12. Hence the G.C.D of 48 and 60 is 12. Directions: Find the G.C.D. of the numbers given in the following questions using the Method of Prime Factors. Also write at least 10 examples of your own. 