Macsen
What is the remainder when a positive integer x is divided by 6?
1. When x is divided by 2, the remainder is 1; and when x is divided by 3, the remainder is 0.
2. When x is divided by 12, the remainder is 3.
I chose B, but the OA says wrong. Can anyone please explain how do we derive a remainder from statement 1? Because from stmt 1, x can be 3 or anything in the form 3n, where n is odd.
Stmnt 1: When x is divided by 2, the remainder is 1; - It means x is odd.
and when x is divided by 3, the remainder is 0. - It means x is divisible by 3
So basically, stmnt 1 tells us that x is an odd multiple of 3 e.g. 3, 9, 15 etc. When you divide these numbers by 6, you will always get 3 as remainder.
Deduce it logically - x i.e. an odd multiple of 3 will always be 3 more than an even multiple of 3 since odd and even multiples of 3 will alternate (e.g. 3 (O), 6(E), 9(O), 12(E), 15(O), 18(E) etc)
Every even multiple of 3 is divisible by 6 so we can say that odd multiples of 3 are always 3 more than multiples of 6. Hence the remainder when you divide x by 6 will always be 3.
Stmnt 2: x is 3 more than a multiple of 12. Since 12 is divisible by 6, x is 3 more than a multiple of 6 too. Hence, remainder is always 3.
Answer (D)