Does anyone know this? I think its B? Am i correct?

Abox of chocolates cost $7 which equation relates the number of boxes sold parentheses x parentheses and total cost of the boxes sold parentheses y parentheses

At school 460 of the students walk to school the number of students who take public transit is 20% of the number of students who walk. how many students take public transit

There were 34 coins in a bag. jim took 15 coins out of the bag. rose put 17 coins into the bag. how many coins are now in the bag?