PLSS HELPP PLSSS AND TY

What is the maximum total area that 450cm of string can enclose if it is used to form perimeters of two adjoining rectangles as shown?

Aresearch group wants to find the opinions’ of city residents on the construction of a new downtown parking garage. what is the population of the survey downtown shoppers downtown visitors downtown workers city residents

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