To make purple food coloring, 3 drops of red can be mixed with 5 drops of blue. To make a larger amount, how many drops of red should be mixed with 30 drops of blue? Berkley solved this problem, as shown. Which best describes his error?

Question

anonymous · Answer

attachment

anonymous · Answer

A)He cross-multiplied incorrectly.

 B)He divided by the wrong number.

 C)He multiplied by the wrong fraction.

 D)He set up the proportion incorrectly

mathstudent55 · Answer

Read the information carefully.
For 3 drops of red he needs 5 drops of blue.
For x drops of red he needs 30 drops of blue.
To set up the proportion, you must make 3 correspond to 5 as x corresponds to 30.
Look at the proportion and see if this is what the proportion is doing.

mathstudent55 · Answer

Where do the 30 and x go in the last fraction?
|dw:1360789662071:dw|