Consider a binary operation ∗ on set{1,2,3,4,5} given by the following multiplication table:
(i)Compute (2∗3)∗4 and 2∗(3∗4)
∗12345111111212121311311412141511115
(ii) Is ∗ commutative?
∗12345111111212121311311412141511115
(iii)Compute (2∗3)×(4ast5)
∗12345111111212121311311412141511115
We have (2∗3)∗4=(1)∗4=1
and 2∗(3∗4)=2∗1=1
For every a,b∈ {1,2,3,4,5},we have a∗b=b∗a.
Therefore, the operation ∗ is commutative
We have (2∗3)=1 and (4∗5)=1
Therefore, (2∗3)∗(4∗5)=1∗1=1