Brandon and Oliver went to buy mobile phones at a sale. The usual price of 1 mobile phone was $1600 each.

SALE
Buy 1 mobile phone at 15% discount
Buy 2 or more mobile phones at 30% discount each

1. Brandon bought 1 mobile phone. How much did he pay?
2. What is the maximum number of mobile phones Oliver can buy if he has $8000?

(a)
Discounted price of 1 mobile phone in percent if only 1 was bought
= 100% - 15%
= 85%

100% of 1 mobile phone = 1600
1% of 1 mobile phone = 1600 ÷ 100 = 16
85% of 1 mobile phone = 85 x 16 = 1360 

Amount that Brandon paid for 1 mobile phone = $1360

(b)
Discounted price of 1 mobile phone in percent if more than 1 was bought
= 100% - 30%
= 70%

70% of 1 mobile phone = 70 x 16 = 1120

Amount that Oliver paid for 1 mobile phone = $1120

Maximum number of mobile phones that Oliver can buy if he has $8000
= 8000 ÷ 1120
= 7 r 160

Answer(s): (a) $1360; (b) 7