Q. If a * b = 2a - 3b + ab, then 3 * 5 + 5 * 3 is equal to :
Answer: 22
Notes: Give that a * b = 2a - 3b + ab $latex => 3 * 5 = 2\times 3 - 3\times 5 + 3\times 5 = 6$ $latex => 5 * 3 = 2\times 5 - 3\times 3 + 3\times 5 = 10 - 9 + 15 = 16$ Therefore, $latex 3 * 5 + 5 * 3 = 6 + 16 = 22$ Hence option [C] is the rigth answer.

4