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The integers \(\mathrm{m}\) and \(\mathrm{p}\) are such that \(2 < \mathrm{m} < \mathrm{p}\), and \(\mathrm{m}\) is not a factor of \(\mathrm{p}\). If \(\mathrm{r}\) is the remainder when \(\mathrm{p}\) is divided by \(\mathrm{m}\), is \(\mathrm{r} > 1\)?
We're asked whether \(\mathrm{r} > 1\), where r is the remainder when integer p is divided by integer m.
Since m doesn't divide p evenly, we know there WILL be a remainder. By the division algorithm, when we divide p by m, we get: \(\mathrm{p} = \mathrm{mq} + \mathrm{r}\), where \(0 < \mathrm{r} < \mathrm{m}\).
The question asks: Is this remainder greater than 1? In other words, is r at least 2?
Since r must be between 1 and (m-1), and we're asking if r > 1, we're really asking: Can r be exactly 1, or must it be 2 or more?
Statement 1: The greatest common factor of m and p is 2.
If \(\mathrm{gcd}(\mathrm{m}, \mathrm{p}) = 2\), then both m and p are even numbers (they both have 2 as a factor).
Here's the key realization: When we divide one even number by another even number, what happens to the remainder?
Think about it this way:
This means: \(2\mathrm{k} = 2\mathrm{j} \times \mathrm{q} + \mathrm{r}\)
Rearranging: \(\mathrm{r} = 2\mathrm{k} - 2\mathrm{jq} = 2(\mathrm{k} - \mathrm{jq})\)
Since r equals 2 times some integer, r must be even!
The remainder r must be:
The smallest positive even number is 2. Therefore, \(\mathrm{r} \geq 2\), which means \(\mathrm{r} > 1\).
[STOP - Statement 1 is SUFFICIENT!]
This eliminates choices B, C, and E.
Now let's forget Statement 1 completely and analyze Statement 2 independently.
Statement 2: The least common multiple of m and p is 30.
If \(\mathrm{lcm}(\mathrm{m}, \mathrm{p}) = 30\), then both m and p must be divisors of 30.
The divisors of 30 are: 1, 2, 3, 5, 6, 10, 15, 30
Given that \(2 < \mathrm{m} < \mathrm{p}\), the possible values for m are: 3, 5, 6, 10, 15
Let's examine two specific cases to see if we always get the same answer:
Case 1: \(\mathrm{m} = 3\)
Case 2: \(\mathrm{m} = 6\)
We found:
Since r can be either equal to 1 or greater than 1, we cannot determine whether \(\mathrm{r} > 1\).
Statement 2 is NOT sufficient.
This eliminates choices B and D.
Statement 1 alone tells us that both m and p are even, which forces the remainder to be even (and therefore at least 2). Statement 2 alone allows for remainders of 1 or greater.
Answer Choice A: Statement 1 alone is sufficient, but Statement 2 alone is not sufficient.