Bunuel wrote:
Is the range of a set of hundred distinct even integers less than 200?
(1) The product of all the numbers in the set is negative.
(2) The product of the smallest and the largest numbers in the set is negative.
Set contains hundred
DISTINCT even integers and we need to determine if the range of this set is less than 200?
An even integer is any integer which is completely divisible by 2 with 0 remainder, and that includes positive, negative and non-negative(0) integers {Ex: -20, -2, 0, 2, 20, 200 etc.}
Taking any set of 100 even integers where range can be less than 200:
1. All positive: From 2 to 200
2. All negative: From -2 to -200
3. All non negative: From 0 to 198
4. All non positive: From 0 to -198
5. Mixed Set 1: -2,0, And then From 2 to 196
6. Mixed Set 2: -2, And then from 2 to 198
Now if you examine all cases above, you can see that the first 5 all scenarios where range is less than 200 is possible but not in the last case. Here is the significance of 0. In the last 2 options, one has 0 in it and another does not and the one which has 0 satisfies range less than 200 and the other does not
So we need to examine the statements based on the conditions above and see how things pan out
(1) The product of all the numbers in the set is negative.Ok, so product of all numbers in the set is negative and since there are an even number (100) of terms in the set, this implies the following
a) Odd number of negative even integers
b) Set contains both positive and negative even integers
c) Set does not contain 0 because else the product would be equal to 0
So based on these, we can safely assume that this falls under category 6 (6. Mixed Set 2: -2, And then from 2 to 198
) mentioned above in which case range cannot be less than 200
SUFFICIENT(2) The product of the smallest and the largest numbers in the set is negative.Ok, so product of smallest and largest numbers is negative which implies the following:
a) Both positive and negative even integers
b) Can or cannot contain 0
So basically this falls under either category 5 or category 6 (5. Mixed Set 1: -2,0, And then From 2 to 196
6. Mixed Set 2: -2, And then from 2 to 198). So range can be less than 200 in case of 0 present in set and cannot be less than 200 if 0 is not present in the set
NOT SUFFICIENTAnswer - A