JAMB - Mathematics (2012 - No. 19)
The binary operation * is defined on the set of integers such that p * q = pq + p - q. Find 2 * (3 * 4)
11
13
15
22
คำอธิบาย
p * q = pq + p - q
First execute for 3 * 4
==> 3(4) + 3 - 4 = 12 + 3 - 4 = 11
Now we execute for 2 * 11
==> 2(11) + 2 - 11 = 22 + 2 - 11 = 13
First execute for 3 * 4
==> 3(4) + 3 - 4 = 12 + 3 - 4 = 11
Now we execute for 2 * 11
==> 2(11) + 2 - 11 = 22 + 2 - 11 = 13