Trigonometry Maze Version 2: Missing Angle Measures

Water flows at a steady rate from a tap. its takes 40 seconds to fill a 4 litre watering can from the tap. the rate at which water flows from the tap is halved. complete: 4 litres into cm3

Which equation results from adding the equations in this system? x+6y=9 and -x+2y=-15

Consider the set of all four-digit positive integers less than 2000 whose digits have a sum of 24. what is the median of this set of integers?