Please solve and give clear explain on and graphing and please ignore writing as it has been done in pen and can't be erased thanks

4. The amount of water (W litres) in a leaking tank after t hours is given by the rule W = -2t + 1000 a. State the gradient and y-intercept for the graph of the rule - -2 X - 1000 b. Sketch the graph of W against t for t between 0 and 500 c. Skate the initial water volume at = 0 160 0 d. Find the volume of water after: i. 320 hours ii. 1 day iii. 1 week e. Find the time take, in hours, for the water volume to fall to: i. 300 litres ii. 185 litres 5. A tank is initially full with 4000L of water and water is being used at a rate of 20L per minute a. Write a rule for the volume, V litres, of water after t minutes b. Calculate the volume after 1.5 hours c. How long will it take for the tank to be emptied? d. How long will it take for the tank to have only 500L? 6. A plumber charges a $40 up-front and $50 for each hour he works a. Find a linear equation for the total charge, $C, for n hours of work b. What will a 4 hour job cost? c. If the plumber work on a job for 2 days, and averages 6 hours per day, what will the total cost