SAT Math: Arithmetic


At an ice cream parlor, customers can add sprinkles and chocolate syrup to their sundaes for free.  If there are 60 customers in one day and 32 chose only sprinkles, 15 chose only chocolate syrup, and 28 chose neither, how many customers chose both sprinkles and chocolate syrup?

A.  0

B.   15

C.   32

D.   43

E.   47


Knowsys Method

Read the question carefully.  There is a lot of information in this problem and you don't want to get it confused.

Identify the bottom line.  How many customers chose both?

Assess your options.  You could try to draw out a Venn diagram, but that will take time and could be confusing.  Instead, use the formula provided in your Knowsys handbook for dealing with two groups.

Attack the problem.  Your Knowsys handbook contains the following formula for 2 groups:

Total = Group 1 + Group 2 + Neither - Both 

Your two groups are sprinkles and chocolate sauce.  Plug the numbers from the problem. 

60 = 32 + 15 + 28 - Both

60 = 75 - Both

Both = 15  

Using the formula, you can get to the answer quickly and easily!

Loop back.  You were asked to solve for both, and that is exactly what you did.  Select your answer.


The correct answer is  (B).

This is a medium level question. 


Want some help reviewing the math concepts you need to master?  Try out the Knowsys Pre-Algebra Flashcards, the Knowsys Algebra I Flashcards, and the Knowsys SAT & ACT Math Practice book.  

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