A cylindrical water tank is 1/5 full. If three liters were added, the tank would be 1/4 full. How many liters does the tank hold when it is full?
+36914 Volume of a cylinder pi r2 h
1/5 full is the 1/5 pi r^2 h
add 3 liters
1/5 pi r^2 h+ 3 = 1/4 pi r^2 h
3 = (1/4 - 1/5 ) pi r^2 h
3 = 1/20 pi r^2 h
60 liters = pi r^2 h = volume when full
