Marc practiced guitar 25 minutes each day in July. In august, he practiced 60 mins per day. Which is the percent increase in Marc’s practice time from July to August

The 7th grade has collected $200 for a field trip that would cost $600. the teachers decided to ask $50 from additional students to cover the cost. how mny students must pay to cover the cost ? a 16studentsb 80studentsc 160studentsd 8students show work