Help me plsss pls​

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

Yvaries inversely as x. y =12 when x=5. find y when x=4

Item 1 which question could the expression 1000n answer? let n = the number of gallons of gas used. how many miles per gallon did the car get driving 1000 miles? let n = the number of grams of food needed for each dog. how many grams of food are needed to feed 1000 dogs? let n = the number of people at the show. how many empty seats were there at the show if there are 1000 seats at the theater? let n = the number of seats at the theater. how many empty seats will there by if 1000 people come to the show?