In 4 ​minutes, a conveyor belt moves 300 pounds of recyclable aluminum from the delivery truck to a storage area. a smaller belt moves the same quantity of cans the same distance in 20 minutes. if both belts are​ used, find how long it takes to move the cans to the storage area.

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]