Select all the correct answers.

A box company completed a study to determine the number of boxes an old machine would produce in an hour. They determined that the old machine produced 280 boxes in 4 hours.

During its first day of operation, a new machine, after running a full 8 hours, produced 56 more boxes than the old machine would have produced in that time.

Which of the following is true about the new machine?

The new machine can produce 14 boxes an hour.
The equation y = 77x represents the production rate of the new machine.
The equation y = 84x represents the production rate of the new machine.
The new machine can produce 7 more boxes an hour than the old machine.

1 answer

To determine the production rate of the old machine, we first calculate how many boxes it produced in one hour.

The old machine produced 280 boxes in 4 hours:

\[ \text{Production rate of old machine} = \frac{280 \text{ boxes}}{4 \text{ hours}} = 70 \text{ boxes per hour} \]

Next, we calculate how many boxes the old machine would produce in 8 hours:

\[ \text{Boxes produced by old machine in 8 hours} = 70 \text{ boxes/hour} \times 8 \text{ hours} = 560 \text{ boxes} \]

It is given that the new machine produced 56 more boxes than the old machine in the same time. Thus:

\[ \text{Boxes produced by new machine in 8 hours} = 560 \text{ boxes} + 56 \text{ boxes} = 616 \text{ boxes} \]

Now, we need to calculate the production rate of the new machine:

\[ \text{Production rate of new machine} = \frac{616 \text{ boxes}}{8 \text{ hours}} = 77 \text{ boxes per hour} \]

Now let's evaluate the given options:

  1. The new machine can produce 14 boxes an hour.

    • False. The new machine produces 77 boxes per hour.
  2. The equation y = 77x represents the production rate of the new machine.

    • True. This indicates that y (the total production) is equal to 77 times x (the number of hours).
  3. The equation y = 84x represents the production rate of the new machine.

    • False. The production rate is 77 boxes per hour, not 84.
  4. The new machine can produce 7 more boxes an hour than the old machine.

    • True. The old machine produces 70 boxes per hour, and the new machine produces 77 boxes per hour; the difference is 77 - 70 = 7.

Based on this analysis, the correct answers are:

  • The equation y = 77x represents the production rate of the new machine.
  • The new machine can produce 7 more boxes an hour than the old machine.