SAT Math Question of the Day

Math Category: Algebraic Sets:

Q: Set C = {3,5,9} and Set D = {2,3,4,7}. What is the union of Set C and Set D?

  1. {0,1,6,8}
  2. {2,3,3,4,5,7,9}
  3. {2,3,4,5,7,9}
  4. {2,3,4,5,8,9}
  5. {2,3,5,7,8,9}

UNANSWERED.

The correct answer is C.

A: {2,3,4,5,7,9} is the correct answer.

To get the union of 2 sets, combine the sets into 1 list, but write each number only once. So the union of {3,5,9} and {2,3,4,7} is {2,3,4,5,7,9}. Answer choice B) {2,3,3,4,5,7,9} is wrong because it lists the number 3 twice.