SAT Mc Graw Hill 2011

1. A speed is a ratio of __ to __. 2. An average is a ratio of __ to __.


2. Define a proportion:

   ---

   
   

   ---

   
   


3. Write the law of cross-multiplication as an “If... then.. .” statement:
   If _____
   then __


4. Write three equations that are equivalent to. 5. a)__
   b)__
   c)__


5. Three people split a $24,000 prize in a ratio of 2:3:5. What is the value of each portion? 6. a)__
   b)__
   c)__


6. A machine, working at a constant rate, manufactures 25 bottles every 6 minutes. 7. ____
   At this rate, how many hourswill it take to produce 1,000 bottles?


7. If mmeteorites enter the Earth’s atmosphere every xdays (m> 0), then, at this rate, 8. ____
   how many meteors will enter the Earth’s atmosphere in mxdays?


8. In the diagram above,
   1 ⏐⏐
   2 , AC=4, BC=5, and CE=6. What is DE? 9. ____


9. There are 12 boys and ggirls in Class A, and there are 27 girls and bboys in Class B. 10. ____
   In each class, the ratio of boys to girls is the same. If b=g,then how many
   students are in Class A?

A

B C

D E

 1

 2

2

x 3

y

=

Concept Review 4: Ratios and Proportions

284 MCGRAW-HILL’S SAT