1. Draw the line N on the diagram above. [2 marks] Jashanti is saving money to buy a car. The price of the car, in US Dollars (USD),
2. can be modelled by the equation
3. P = 8500 (0.95)t.
4. Jashanti's savings, in USD, can be modelled by the equation
5. S = 400t + 2000.
6. In both equations t is the time in months since Jashanti started saving for the car.

10a. Write down the amount of money Jashanti saves per month. [1 mark]

10b. Use your graphic display calculator to find how long it will take for [2 marks] Jashanti to have saved enough money to buy the car.

Jashanti does not want to wait too long and wants to buy the car two months after she started saving. She decides to ask her parents for the extra money that she needs.

10c. Calculate how much extra money Jashanti needs.