Atutor schedules either 30-minute sessions or 60-minute sessions with her students. last week, the tutor gave 8 sessions which lasted for a total of 7 hours. how many 60-minute sessions did the tutor give last week?

She gave 1 60 minute session. You will take 7 and multiply times 60 and get 420. There are 420 min in 7 hours. Then you will take those 8 days of tutoring and multiply times those 420 minutes and get 3,360 minutes. You will then take that and divide by 60 and you get 56 so then you know you can not have another 60 minute session that week. 

Num of plants = (original#ofplants)*(1.6)^t