Please help

JOHAN (CA-FINAL) (277 Points)

20 April 2012  

An asset has an useful life of 4 years.The asset is depreciated by written down value method.The book value at the end of4th year is12% of the original cost.The rate of depreciation is-

a,41% b,30% c,12% d,24%........ pls show the steps of the ans.........