Is the integer p divisible by 4?
(1) p < 123
(2) p is the product of 5 consecutive positive integers.
The OA is B.
Clearly statement (1) is not sufficient. But, how can I ensure the statement (2) is sufficient?
Is the integer p divisible by 4?
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Statement 2: p is the product of 5 consecutive positive integers.Vincen wrote:Is the integer p divisible by 4?
(1) p < 123
(2) p is the product of 5 consecutive positive integers.
The OA is B.
Clearly statement (1) is not sufficient. But, how can I ensure the statement (2) is sufficient?
If you take any five consecutive positive integers, you are sure to get minimum two EVEN positive integers. Since every even number is a multiple of 2, we get at least two 2s. Thus, p = Product of 5 consecutive positive integers is divisible by 4. Sufficient.
Example:
Case 1: Say the five consecutive positive integers are: 1, 2, 3, 4, 5. We see that the product of 2*4 = 8, thus, p = Product of 5 consecutive positive integers is divisible by 4.
Case 2: Say the five consecutive positive integers are: 17, 18, 19, 20, 21. We see that the product of 18*20 = 8*45, thus, p = Product of 5 consecutive positive integers is divisible by 4.
Hope this helps!
-Jay
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If you're multiplying five consecutive integers together, then at least two of them must be even. Since you've got at least two evens, you've got:
2*something * 2*something else =>
4*something*something else =>
a multiple of 4
2*something * 2*something else =>
4*something*something else =>
a multiple of 4