Respuesta :
The answer is 1.5 minutes
let t = time required when both belts are used
Let the completed job = 1 (moving 300 lb)
1/2+1/6=1
Multiply by 6
6*t/2 + 6*t/6 = 6
6t/2+6t/6=6
3t + 1t = 6
4t = 6
t = 6/4
t = 1.5 min
Answer:
t = 3.33 minutes
Explanation:
We need to move 300 pounds of material
The large conveyor takes 4 minutes to complete the task.
So we can say in one minute it will complete [tex]\frac{1}{4}[/tex] of the task
The small conveyor takes 20 minutes to complete the task
So in one minute it completes [tex]\frac{1}{20}[/tex] of the task
When combined they will complete a certain fraction of work
Let us call it x
[tex]X = \frac{1}{4} +\frac{1}{20} \\\\X = \frac{6}{20}[/tex]
Time taken to complete the task
[tex]t = \frac{1}{X} \\\\t = \frac{1}{\frac{6}{20} } \\\\t = \frac{20}{6} \\\\t = 3.33 minutes[/tex]