ISEE Mathematics Achievement Question 312: Answer and Explanation

Home > ISEE Test > ISEE Mathematics Achievement Practice Tests

Test Information

Question: 312

12. Anthony has twice as many baseball cards as Keith, who has one-third as many baseball cards as Ian. If Keith has k baseball cards, how many baseball cards do Anthony and Ian have together?

  • A.
  • B.
  • C.
  • D.

Correct Answer: D

Explanation:

D This is a Plugging In question because there are variables in the choices and the question stem contains the phrase in terms of. Plug In a value, work through the problem to find a target answer, and then check each of the choices to see which yields the target answer. For instance, Plug In 20 for Anthony. Since Anthony has twice as many baseball cards as Keith, Keith has the number of cards that Anthony has. Therefore, Keith must have 10 cards, and k = 10. Keith has one-third as many baseball cards as Ian, so Ian has 3 times as many as Keith has: 10 × 3 = 30, or 30 cards. Together, Anthony and Ian have 20 + 30 = 50. So, 50 is the target answer. Now, Plug In 10 for k to find which choice yields 50, your target answer. Eliminate (A) because = = 15, not 50. Eliminate (B) because = = 30 is still too small. Choice (C) is still too small, as = = 40. Choice (D) works because = = 50. The correct answer is (D).

Previous       Next