Jeremy and Luke went to buy hi-fi systems at a sale. The usual price of 1 hi-fi system was $2000 each.

SALE
Buy 1 hi-fi system at 5% discount
Buy 2 or more hi-fi systems at 10% discount each

1. Jeremy bought 1 hi-fi system. How much did he pay?
2. What is the maximum number of hi-fi systems Luke can buy if he has $6000?

(a)
Discounted price of 1 hi-fi system in percent if only 1 was bought
= 100% - 5%
= 95%

100% of 1 hi-fi system = 2000
1% of 1 hi-fi system = 2000 ÷ 100 = 20
95% of 1 hi-fi system = 95 x 20 = 1900 

Amount that Jeremy paid for 1 hi-fi system = $1900

(b)
Discounted price of 1 hi-fi system in percent if more than 1 was bought
= 100% - 10%
= 90%

90% of 1 hi-fi system = 90 x 20 = 1800

Amount that Luke paid for 1 hi-fi system = $1800

Maximum number of hi-fi systems that Luke can buy if he has $6000
= 6000 ÷ 1800
= 3 r 600

Answer(s): (a) $1900; (b) 3