Answer:
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 = \(\frac{1}{120}\) hours.
then by definition of unit rate;
\(\text{Unit rate per hour} = \frac{20}{\frac{1}{120}}= 20 \cdot 120 = 2400\)
we have to find the number of boxes can the machine fill in 2 hours.
\(\text{Number of pencils} = \text{Unit rate per hour} \times 2\)
Substitute the given values we have;
\(\text{Number of pencils} = 2400 \times 2 = 4800\)
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
