[email protected] wrote:How many integers n are there such that r<n<s?
1) s-r=5
2) r and s are nor integers
Target question: How many integers n are there such that r < n < s? [/color]
Statement 1: s - r = 5
There are two cases we need to consider.
Case a: s and r are integers.
For example, s=6 and r=1, in which case
there are 4 integers between r and s (2, 3, 4 and 5)
Case b: s and r are not integers.
For example, s=6.1 and r=1.1, in which case
there are 5 integers between r and s (2, 3, 4, 5, and 6)
Since we cannot answer the
target question with certainty, statement 1 is NOT SUFFICIENT
Statement 2: r and s are not integers
This is definitely not enough information here to answer the target question.
Consider these 2 cases.
Case a: r=1.1 and s=2.1, in which case
there is 1 integer between r and s (2)
Case b: r=1.1 and s=3.1, in which case
there are 2 integers between r and s (2 and 3)
Since we cannot answer the
target question with certainty, statement 2 is NOT SUFFICIENT
Statements 1 and 2 combined:
From statement 1, we know that there are either 4 or 5 integers between r and s,
depending on whether or not r and s are integers.
Statement 2 rules out the possibility that r and s are integers.
If r and s are non integers, then
there must be 5 integers between r and s
Since we
can answer the
target question with certainty, the combined statements are SUFFICIENT
Answer =
C
Cheers,
Brent
