Question

If a binary operation * is defined on the set Z of integers as a * b = 3a − b, then the value of (2 * 3) * 4 is ___________ .

Options

• 2

• 3

• 4

• 5

Answer 1

5
Given: a * b = 3a − b
2 * 3 = 3 (2) \[-\] 3
         = 6 \[-\] 3
         = 3

(2 * 3) * 4 = 3 * 4
         = 3 (3) \[-\] 4 

         = 9 \[-\] 4

         = 5