They are both correct becuase lets say it was a shirt that was $30 and it was 30% off. For Jasani it would be 30 * 0.7 which equals $9 then you would subtract this 30 - 9 = 21. For Hanna it would be 30 - 0.3(30) which equals $21. So in the end they are both correct!
No
THE P IS SOMETHING U NEED TO PLUG IN