Question

You buy a new computer for $2100. The computer decreases by 50% annually. When will the computer have a value of $600?

Answer 1

There is few ways to get the result. The easiest is calculating step by step (year by year) price of the computer.
50%=0.5 (in decimal)
2100*0.5=1050 - 1 year
1050*0.5=525 - 2 year
The result it 2 years.
To get more accurate result we can solve equation

`2100*( (1)/(2))^x=600`
but its very hard to solve without powerful tool.