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SAT Math Strategy: Plugging in the Answers

SAT Question of the Day

Today’s question is a math question.

1. Read the Question Carefully:  There is a lot going on here and you don’t want to miss any piece of information.  You know that there are 10 cars carrying a total of 32 people.  None of the cars have more than 4 people in them.

2. Identify the Bottom Line: What is the greatest number of cars that could contain 2 people?

3. Assess your Options:  The fastest way to work this problem is to use logic and your Knowsys strategies.  If all 10 cars carried 2 people, there would only be 20 people.  You know that there are 32 people, so you need to cram as many people as possible (4) into any car that is not carrying 2 people.  Your total number of cars must always be 10.

Take a peek at your answer choices.  You want the biggest number possible, so use the strategy of plugging in your biggest answer choice.  Your biggest answer choice is (E).

4.  Attack the Problem:  

(E)  Will 5 cars holding 2 people work?  If you have 5 cars with 2 people and 5 cars with 4 people, then that is only a total of 30. (You could write the equation 5 × 2 + 5 × 4 = 30) You need a total of 32 people.  Eliminate this answer choice.

(D)  Will 4 cars holding 2 people work?  If you have 4 cars with 2 people and 6 cars with 4 people, then you have a total of 32 people.  (4 × 2 + 6 × 4 = 32) You found your answer!

5:  Loop Back to the Bottom Line:  You fulfilled all of the requirements for this problem.  You found the biggest possible number of cars carrying 2 people if there are 10 total cars and 32 people.

The correct answer is (D).

Note:  On sat.collegeboard.org, 38% of the responses were correct.  The explanation on this site will get you to the correct answer, but it takes too long.  On a timed test, the long way is the wrong way.

ACT Question of the Day

The ACT question of the day is an English question that has already been addressed on this blog: click here to see an explanation.

To get help preparing for the SAT, PSAT, or ACT exam, check out the Knowsys College Readiness Program.

For help with the SAT Vocabulary, check out our flashcardsflashcard apps, and iBook activities.