Consider the binary operation * on the set {1, 2, 3, 4, 5} defined by a*b=HCF of a andb. Write the operation table of the operation *. Is * commutative? Justify. Also, compute: (a) (2*3)*5 (b) (2*3)*(4*5). 

Asked by niharikapabba2605 | 12th Oct, 2018, 07:21: PM

Expert Answer:

According to the question, binary operation on the set {1, 2, 3, 4, 5} can be given as follows where a*b = HCF of a and b
(2*3)*5
= 1 * 5                 HCF of 2 and 3 is 1
= 1                       HCF of 1 and 5 is 1

Answered by Sneha shidid | 15th Oct, 2018, 10:41: AM