Owen and Japheth went to buy mobile phones at a sale. The usual price of 1 mobile phone was $200 each.

SALE
Buy 1 mobile phone at 5% discount
Buy 2 or more mobile phones at 15% discount each

1. Owen bought 1 mobile phone. How much did he pay?
2. What is the maximum number of mobile phones Japheth can buy if he has $5000?

(a)
Discounted price of 1 mobile phone in percent if only 1 was bought
= 100% - 5%
= 95%

100% of 1 mobile phone = 200
1% of 1 mobile phone = 200 ÷ 100 = 2
95% of 1 mobile phone = 95 x 2 = 190 

Amount that Owen paid for 1 mobile phone = $190

(b)
Discounted price of 1 mobile phone in percent if more than 1 was bought
= 100% - 15%
= 85%

85% of 1 mobile phone = 85 x 2 = 170

Amount that Japheth paid for 1 mobile phone = $170

Maximum number of mobile phones that Japheth can buy if he has $5000
= 5000 ÷ 170
= 29 r 70

Answer(s): (a) $190; (b) 29