The counting number ABAB is a multiple of 36. If different letters represent different digits, what is the greatest value ABAB can have? PLS HELP ONLY 10 minutes

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

8. kelly wants to buy a magazine that is $25. later the magazine was marked up an additional 20%. what is the new price?

Which geometric principle is used to justify the construction below?