1. (a) None (b) One (c) Infi nite (d) One (e) None
2. (a) x = 8, y = 13 (b) x = 11/5 ; y = 2/5 (c) x = 1/17 , y = - 5/17
3. Peter is 15, Anneka is 9
Additional Questions
- A coach travels along the M3 from Winchester to London. It sets off at 10.30 a.m and travels at a constant speed of 65 mph. A car makes the same journey, travelling 10 mph faster but leaving 5 minutes later. When does the car overtake the coach?
- Andrea is trying to save money on electricity bills. at present she estimates her family uses 8000 units of electricity per year at 6.59 cent per unit. They also have to pay an annual standing charge of $36.28. She is told that installing an ' Economic 7' system might save money. This mean that off-peak units are charged at 2.63 cent per unit and the rest at 6.59p, but there is an additional annual standing charge of $10.04. She wants to know how many of the 8000 units would have to be off-peak units in order to save at least $50 per year. Solve her problem.
