Answer: 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.
Answer:
10,935 meters.
Step-by-step explanation:
Find how many meters she walks in 1 week, so you add the 1,720 and the 1,925 and you would get 3,645. If she does the same thing for 3 weeks, you multiply the 3,645 by 3, so you get 10,935 meters
First we rewrite the expression correctly:
tn = ((-1) ^ n) * (n)
We now look for each of the terms:
t1 = ((-1) ^ 1) * (1) = - 1
t2 = ((-1) ^ 2) * (2) = 2
t3 = ((-1) ^ 3) * (3) = - 3
t4 = ((-1) ^ 4) * (4) = 4
The first four terms of the sequence are then:
-1, 2, -3, 4
Answer:
B.
-1, 2, -3, 4