8. An inflatable raft is dropped from a hovering helicopter to a boat in distress below. The height of the raft above the water, in metres, is approximated by the equation:

h=500-5t2, where t is the time in seconds since the raft was dropped.

1. What is the height of the helicopter above the water?
2. When does the raft reach the water?
3. What is the height of the raft above the water 6 seconds after it is dropped?

9. Rahj owns a hardware store. For every increase in 10in the price of a package of batteries, he estimates that sales decrease by 10 packages per day. The store normally sells 700 packages of batteries per day at $5.00 per package.

1. Determine an equation for revenue, R, when x number of 10increases are made in the price.
2. When does Rahj make a revenue of $0? Explain both scenarios.
3. What is the maximum daily revenue that Rahj can expect from battery sales?
4. How many packages of batteries are sold when the revenue is at maximum?