If s and t are two different numbers on the number line, is s+t = 0?
1) The distance between s and 0 is same as the distance between t and 0
2) 0 is between s and t
Trivial number line
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Ans C
We need to show that s+t = 0 only possible if one is +ve and other is the -ve value of it. or s=-t
St 1
s=t or s=-t
St 2
Don't know if they are same values
St1 and St2
s=-t
We need to show that s+t = 0 only possible if one is +ve and other is the -ve value of it. or s=-t
St 1
s=t or s=-t
St 2
Don't know if they are same values
St1 and St2
s=-t
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I'll go with A
Given: s and t are 2 different numbers.
Asked: is s+t = 0 or is s = -t?
St 1: s cannot be equal to t (since they are 2 different numbers)
So the only option left is s = -t.
So St 1 is suff.
St 2: it just means that the 2 numbers have opposite signs.
So St 2 is insuff.
Given: s and t are 2 different numbers.
Asked: is s+t = 0 or is s = -t?
St 1: s cannot be equal to t (since they are 2 different numbers)
So the only option left is s = -t.
So St 1 is suff.
St 2: it just means that the 2 numbers have opposite signs.
So St 2 is insuff.
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Attempted this question today. I like the title "Trivial number line".
As per (1), if distance of s and t from 0 is the same (and it is given that s and t are "different" numbers), then it has to be the case that one is positive and the other is negative and they are equi-distance from 0.
=> s + t = 0
Sufficient.
As per (1), 0 is between s and t. This obviously does not tell us anything about the actual values. For example, it is possible that s = 5, t = -1; or it is possible that s = 5, t = -5.
Insufficient.
Hence, A.
As per (1), if distance of s and t from 0 is the same (and it is given that s and t are "different" numbers), then it has to be the case that one is positive and the other is negative and they are equi-distance from 0.
=> s + t = 0
Sufficient.
As per (1), 0 is between s and t. This obviously does not tell us anything about the actual values. For example, it is possible that s = 5, t = -1; or it is possible that s = 5, t = -5.
Insufficient.
Hence, A.
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A is correct here. Remember to pay attention to every bit of information you're given in the question stem; even little phrases like "two different numbers" can completely change the solution to a DS problem.