How much the entire earth cost?

Expresa commuter train leaves downtown sation and travels at a average speed of 55 miles per hour towards the north side sation, which is 50miles away. thirty minutes later, express commuter train #7 leaves north side and travels at a average speed of 35miles per hour towards downtown sation. at the moment the two trains pass each other, how far(in miles) is train #12 from the downtown sation and how long(in minutes) has the #12 train been traveling

Collin did the work to see if 10 is a solution to the equation r/4=2.4

We have 339 ounces of jam to be divided up equally for 12 people how muny ounces will each person get