A cargo grain leaves Chicago at noon travelling west at 120 km/h. At 2 pm, a passenger train leaves Chicago travelling east at 360km/h. What time will it be when the trains are 1520 km apart? At that time, what distance has each train travelled?

a) The trains will be 1520 km apart at 2:40 pm for the cargo train and at 4:40 pm for the passenger train.

b) At that time the cargo train has traveled 560.04 km and the passenger train has traveled 960.12 km.

Step-by-step explanation:

a) First, we need to find the distance traveled by the cargo train in the two hours before the passenger train leaves Chicago:

Now, we can find the time when the trains will be 1520 km apart:

Where 1 is for the cargo train and 2 is for the passenger train.

Since we need to calculate the time when the trains are 1520 km apart, t₁ = t₂, so:

For the cargo train, it will be 1520 km apart from the passenger train at:

And for a passenger train, it will be 1520 km apart from the cargo train at:

Hence, the trains will be 1520 km apart at 2:40 pm for the cargo train and at 4:40 pm for the passenger train.  

b) The distance traveled by both trains is given by:

Therefore, at that time the cargo train has traveled 560.04 km and the passenger train has traveled 960.12 km.

I hope it helps you!        

the answer is c. 23/3

answer:

c. the third graph