Can someone help me please

Look at arnold's attempt to solve the equation for b: 3b = 12 b = 3 · 12 b = 36 describe the mistake that arnold made.

40) linda was making chocolate truffles for the first day of school. the recipe for 20 chocolate truffles is: i cup of cream 2 cups of dark chocolate she noticed this will not be enough truffles for the 42 sure that all students in each homeroom next year. to be sure that all students receive a truffle, linda must adjust her recipe. a. complete the recipe for 42 truffles cups of cream - cups of dark chocolate work:

Me with this assignment ! i only partially understand, so explain. also it's a work sample. at the championship bike race, steve and paula were fighting for first place. steve was 175 feet ahead of paula and had only 300 feet left to go. he was very tired and was going only 9 feet per second. paula was desperate to catch up and was going 15 feet per second. who won the bike race and by how far did she/he win?