Hello, Here's a question from Princeton Review:
If P is a set of integers and 3 is in P, is every positive multiple of 3 in p?
1. For any integer in P, the sum of 3 and that integer is also in P.
2. For ant integer in P, that integer minus 3 is also in P.
The answer is A.
My answer was E based on the following argument.
3 is in P. Taking first statement into consideration, lets take a number, say x and assume that it is in P. So we will have x+3 also in P. We dont have any information whether x or x+3 is a multiple of 3. If x = 6 then both ARE multiples, however if x = 5, both will not be. We know that a number and its sum with 3 are in the set but we have no clue, what are the other numbers in the set.
Taking second statement into consideration, it will work absolutely the same way as first.
Can somebody help me understand the reason behind the correct answer or is my answer correct?
As far as SC is concerned is there any flaw in my question above - Can somebody help me understand the reason...
I like to practice SC this way.
If P is a set of integers and 3 is in P, is every positive multiple of 3 in p?
1. For any integer in P, the sum of 3 and that integer is also in P.
2. For ant integer in P, that integer minus 3 is also in P.
The answer is A.
My answer was E based on the following argument.
3 is in P. Taking first statement into consideration, lets take a number, say x and assume that it is in P. So we will have x+3 also in P. We dont have any information whether x or x+3 is a multiple of 3. If x = 6 then both ARE multiples, however if x = 5, both will not be. We know that a number and its sum with 3 are in the set but we have no clue, what are the other numbers in the set.
Taking second statement into consideration, it will work absolutely the same way as first.
Can somebody help me understand the reason behind the correct answer or is my answer correct?
As far as SC is concerned is there any flaw in my question above - Can somebody help me understand the reason...
I like to practice SC this way.
