Question

A machine can fill a box with twenty pencils in 30 seconds. How many boxes can the machine fill in 2 hours?

Answer 1

4800 pencils or 240 boxes

Answer 2

use conversion:

1 hour = 3600 seconds.

As per the given statement:

A machine can fill a box with twenty pencils in 30 seconds.

Number of pencils = 20

Time = 30 seconds =
`(1)/(120)` hours.

then by definition of unit rate;

`\text{Unit rate per hour} = (20)/((1)/(120))= 20 \cdot 120 = 2400`

we have to find the number of boxes can the machine fill in 2 hours.

`\text{Number of pencils} = \text{Unit rate per hour} * 2`

Substitute the given values we have;

`\text{Number of pencils} = 2400 * 2 = 4800`

it is given that:

20 pencils fill = 1 box

4800 pencils fill = 240 boxes

Therefore, 240 boxes can the machine fill with 4800 pencils in 2 hours