SAT Math Multiple Choice Practice Question 53: Answer and Explanation
9. Getting ready for a party, Nandan expected to set up 1/3 of the tables needed. Unfortunately, one of the people helping him did not show up. As a result, he now had to set up 1/2 of the tables. If he had to set up 4 more tables than he expected, what was the total number of tables set up for the party?
Correct Answer: D
D. You could write an algebra equation for this problem, but reasoning it out works fine, too. The fraction of the tables that Nandan had to set up changed from 1/3 to 1/2. In math, change is always a cue to subtract, and 1/2 - 1/3 = 1/6. (Solve this without a calculator just for the practice.) So Nandan had to set up 1/6 more tables than he expected — 4 tables, according to the problem. If 4 is 1/6 of the total, then the total number of tables is 4 × 6 = 24.