Question

A laptop computer is purchased for $2100. Each year, its value is 75% of its value the year before. After how many years will the laptop computer be worth$300 or less?

Answer 1

After the first year, the price of the laptop computer is;

`P_1=0.75*2100=1575`

After the second year, the price of the laptop computer is;

`P_2=0.75*1575=1181.25`

After the third year, the price of the laptop computer is;

`P_3=0.75*1181.25=885.94`

After the fourth year, the price of the laptop computer is;

`P_4=0.75*885.94=664.45`

After the fifth year, the price of the laptop computer is;

`P_5=0.75*664.45=498.34`

After the sixth year, the price of the laptop computer is;

`P_6=0.75*498.34=373.75`

After the seventh year, the price of the laptop computer is;

`P_7=0.75*373.75=280.32`

CORRECT ANSWER: 7 years