Question

Type the correct answer in each box. Use numerals instead of words.

In Joey's neighborhood, the ratio of families with dogs to families with cats is 5 to 2. There are 15 more families with dogs than families with cats.

In Joey's neighborhood
_____ families have cats
and_____ families have dogs.

Answer 1

9514 1404 393

Answer:

• 10 families have cats
• 25 families have dogs

Explanation:

The difference of ratio units is 5-2 = 3. The difference in pet counts is 15, so we can see that each ratio unit stands for 15/3 = 5 pets. Then ...

dogs : cats = 5 : 2 = (5·5) : (2·5) = 25 : 10

There are 10 families with cats and 25 families with dogs.

_____

You could write the equations:

d/c = 5/2

d - c = 15

Solving the first for d, you get ...

d = (5/2)c

Substituting that into the second gives ...

(5/2)c -c = 15

3/2c = 15

c = (2/3)(15) = 10 . . . . . cat families

d = (5/2)c = 5/2·10 = 25 . . . . dog families