Question:
If x +y + z = 6 and z is an odd digit, then the three-digit number xyz is
(a) an odd multiple of 3
(b) an odd multiple of 6
(c) an even multiple of 3
(d) an even multiple of 9
Solution:
(a) We have, x + y+ z= 6 and z is an odd digit. Since, sum of the digits is divisible by 3, it will also be divisible by 2 and 3 but unit digit is odd, so it is
divisible by 3 only.Hence, the number is an odd multiple of 3.