Ron's recycle shop had an old paper-shredding machine. business was good, so he bought a new paper-shredding machine. the old machine could shred a truckload of paper in 4 hours. the new machine could shred the same truckload in 2 hours. how long will it take to shred the same truckload of paper if ron runs both shredders at the same time?

1 hour 20 minutes

Step-by-step explanation:

Given : The old machine could shred a truckload of paper in 4 hours.

Rate of work done by old machine =

The new machine could shred the same truckload in 2 hours.

Rate of work done by new machine =

Let 't' be the time taken by both of them working together , then we have the following equation:-

Since 1 hour = 60 minutes

Then,

Hence, it will take 1 hour 20 minutes to shred the same truckload of paper if Ron runs both shredders at the same time.

1. d.90

2. e. none of these (80)

3. a. 0

4. b. 6

5. e. none of these (10)

6. a. 5

where are the choices?