**Depreciation**- An alternative to straight-line depreciation is declining balance depreciation. This method assumes that an item loses value more steeply at the beginning of its life than later on. A fixed percentage of this value is subtracted each year. Suppose an item's initial cost is C, and its useful life is N years. Then the value, V (in dollars), of the item at the end of

*n*years is given by...

V = C (1 - 1/N)

^{n}

where each year brings a depreciation of 100/N percent. (This is called single declining depreciation. If the annual depreciation were 200/N percent, that would be double declining balance.)

If a new photocopier is purchased for $2145 and has a useful life of 6 years, after how many years does its value drop below $900? Give the answer rounded up to the nearest integer.

If a new photocopier is purchased for $2145 and has a useful life of 6 years, after how many years does its value drop below $900? Give the answer rounded up to the nearest integer.

I don't have the slightest clue how to approach it, and neither does my friend. My tutorial is Monday afternoon, so if anyone could give any help to this, that'd be great. =]