What’s 2? i need lots of help with this hw!!

Ineed with number 6 , explain how to get 1978

I’m on question 7 it says a covered water tank is in the shape of a cylinder the tank has a 28 inch diameter and a height of 66 inches to the nearest square inch what is the surface area of the water tank

In the sixth grade 13 out of 20 students have a dog if there are 152 sixth grade students how many of them have a dog