# SSAT Middle Level Math : How to find a ratio

## Example Questions

### Example Question #11 : Find A Percent Of A Quantity As A Rate Per 100: Ccss.Math.Content.6.Rp.A.3c

Red is a very popular car color. A production company manufactures cars and parks them in a lot behind the plant. There are  cars in the parking lot and  of them are red. How many red cars are in the parking lot?

Explanation:

We can use ratios and proportions to solve this problem. Percentages can be written as ratios. The word “percent” means for every hundred. In the problem, we are told that  of the cars are red. In other words, for every hundred cars  of them are red. We can write the following ratio:

Reduce.

We know that there are  cars in the parking lot. We can write the following ratio by substituting the variable  for the number of red cars:

Now, we can create a proportion using our two ratios.

Cross multiply and solve for .

Simplify.

Divide both sides of the equation by .

Solve.

There are  red cars in the parking lot.

### Example Question #111 : How To Find A Ratio

A motorcyclist travels  in . What is the motorcyclist’s speed in miles per hour (mph)?

Explanation:

In order to find the motorcyclist’s speed, we need to create a ratio of the miles travelled in a single hour.

Reduce and solve.

### Example Question #11 : Understand The Concept Of A Ratio: Ccss.Math.Content.6.Rp.A.1

Candidate A receives  votes for every  vote that candidate B receives. At the end of the election candidate B has  votes. How many votes did candidate A get?

Explanation:

In order to solve this problem we need to create a ratio with the given information. It says that for every  votes cast for candidate A, candidate B got  vote. We can write the following ratio.

Now substitute in the given numbers.

Now, use the original relationship to create a proportion and solve for the number of votes that candidate A received.

Cross multiply and solve for .

Simplify and solve.

### Example Question #111 : How To Find A Ratio

Candidate A receives  votes for every  vote that candidate B receives. At the end of the election candidate B has  votes. How many votes did candidate A get?

Explanation:

In order to solve this problem we need to create a ratio with the given information. It says that for every  votes cast for candidate A, candidate B got  vote. We can write the following ratio.

Now substitute in the given numbers.

Now, use the original relationship to create a proportion and solve for the number of votes that candidate A received.

Cross multiply and solve for .

Simplify and solve.

### Example Question #1 : Understand The Concept Of A Unit Rate: Ccss.Math.Content.6.Rp.A.2

A motorcycle travels  in . What is the motorcyclist’s speed in miles per hour (mph)?

Explanation:

In order to find the motorcyclist’s speed, we need to create a ratio of the miles travelled in a single hour.

Reduce and solve.

### Example Question #42 : Ratios & Proportional Relationships

Traffic from the suburbs into a city typically follows an observable pattern. On any given morning there are  cars on the road for every  trucks on the road. On Monday morning there are  trucks on the road. How many cars are on the road?

Explanation:

In order to solve this problem we must make a table of ratios. In the question we are given the base ratio:

We can use this ratio to make a table.

According to the table, there are .

### Example Question #111 : How To Find A Ratio

The ratio of boys to girls in Ms. Smith’s class is 5:4. If there are 20 girls, how many boys are in the class?

Explanation:

One way to solve this problem is to use cross multiplication. Set the ratio of   to solve for the number of boys in the class.

Therefore,

Therefore, there are 25 boys in the class.

### Example Question #112 : How To Find A Ratio

There are 50 pieces of fruit in a fruit basket. There are 22 apples, the rest are oranges. What is the ratio of oranges to apples?

Explanation:

First we need to determine how many pieces of fruit are oranges. To do this, we subtract:

Therefore the ratio of

This ratio can be simplified by dividing each side by 2. The ratio is then .

### Example Question #111 : How To Find A Ratio

There are 50 orange cats and 20 black cats. What is the ratio of black to orange cats?

Explanation:

The number of black cats goes before the colon since this question is asking for the ratio of black to orange cats.

Therefore, there are .

This can be simplified if you divide both numbers by 10. This gives a ratio of .

Find .