A music store buys instruments and then sells them for 30% more than they paid. If the price tag on a trumpet says 104, how much did the store pay for it?

Passengers usually start to board their flights 1 hour before the scheduled take off time. the gate will be closed 15 minutes before the takeoff time. jack’s plane is scheduled to take off at 12: 05 a.m. if he arrives at the gate at 11: 45 p.m., can he board the flight?

This is different from the first one can someone me

Explain how you can use the associative property to evaluate (7x50)x4.