Odd SAT math questions (math rules, really)

Discus: SAT/ACT Tests and Test Preparation: April 2004 Archive: Odd SAT math questions (math rules, really)
 By Brum (Brum) on Friday, April 30, 2004 - 10:08 pm: Edit

2 questions:

a) What are sets (the things that are like {1, 3, 8} )? And can you have numbers repeated in a set?

b) What's the rule for the lengths of the sides of a triangle?

it's something like:

The sum of the lengths of any two sides must be greater than (OR IS IT GREATER THAN OR EQUAL TO?) the length of the 3rd side.

Thanks!

 By Zzii (Zzii) on Friday, April 30, 2004 - 10:41 pm: Edit

a) just a collection of numbers. for example the set of all positive multiples of 2 would be {2,4,6,8,...}. a set of all positive integers would be {1,2,3,4,5,...} Not sure about the repeated numbers...anyone else know?

a set is considered CLOSED under a certain operation if any two numbers in the set that undergo that operation result in a third number that is part of that set. For example, the set of all positive integers is closed for addition. Any positive integer + any other positive integer gives a third positive integer. The set of all positive integers is NOT CLOSED for division. 1 / 2 = 0.5 which is not an integer.

b) the sum of the length of two sides of a triangle must be greater than the length of the third side. if they were equal, it would be a straight line.