A circle has circumference of 11,304 units what is the diameter of the circle

10 ! a train starts from grand city and travels toward belleville 388 miles away. at the same time, a train starts from belleville and runs at the rate of 47 miles per hour toward grand city. they pass each other 4 hours later. find the rate of the train from grand city.

The ph level of a blueberry is 3.1 what is the hydrogen-ion concentration [h+] for the blueberry

I’m confused on how to work the pie charts