Q11 of 123 Page 3

Mark the correct alternative in each of the following:

Let * be a binary operation defined on set Q – {1} by the rule a * b = a + b – ab. Then, the identity element for * is


For Identity element a * e = a = e * a , with ‘e’ being the identity element.


Given


⇒ a * e =a + e – ae


=a


⇒ a + e - ae=a


⇒ e(1-a) =0


⇒ e=0

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Mark the correct alternative in each of the following:

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The binary operation * defined on N by a * b = a + b + ab for all a, b ∈ N is