Select ALL the correct answers.

The ratio of the number of children to the number of adults watching a movie in a theater is 2:5. There are 280 people watching the movie. Which statements are true for this situation?
There are exactly 120 more adults than children.
There are exactly 120 children watching the movie.
Two-fifths of the people watching the movie are children.
The number of children is of the number of adults.
Five-sevenths of the people watching the movie are adults.

1 answer

To analyze the situation, we have a ratio of children to adults of 2:5. This means that for every 2 children, there are 5 adults.

First, we'll start by letting \(2x\) represent the number of children and \(5x\) represent the number of adults. The total number of people watching the movie can be expressed as:

\[ 2x + 5x = 7x \]

Given that there are 280 people in total, we can set up the equation:

\[ 7x = 280 \]

Solving for \(x\):

\[ x = \frac{280}{7} = 40 \]

Now we can find the number of children and adults:

  • Number of children: \[ 2x = 2(40) = 80 \]
  • Number of adults: \[ 5x = 5(40) = 200 \]

Now we can evaluate each of the statements:

  1. There are exactly 120 more adults than children. \[ 200 - 80 = 120 \quad \text{(True)} \]

  2. There are exactly 120 children watching the movie. \[ \text{(False: There are actually 80 children)} \]

  3. Two-fifths of the people watching the movie are children. \[ \text{Fraction of children} = \frac{80}{280} = \frac{2}{7} \quad \text{(False: It is not two-fifths)} \]

  4. The number of children is \(\frac{2}{5}\) of the number of adults. \[ \text{Fraction of children to adults} = \frac{80}{200} = \frac{2}{5} \quad \text{(True)} \]

  5. Five-sevenths of the people watching the movie are adults. \[ \text{Fraction of adults} = \frac{200}{280} = \frac{5}{7} \quad \text{(True)} \]

The correct statements are:

  • There are exactly 120 more adults than children.
  • The number of children is \(\frac{2}{5}\) of the number of adults.
  • Five-sevenths of the people watching the movie are adults.

So the true statements are: 1, 4, and 5.