Ajet ski costs $925 and depreciates by 15% each year. how much will
the jet ski be worth after 7 years?

Initial cost of the jet ski = $925
Percentage of depreciation per year = 15%
Number of years after which the cost of the jetski has to be determined = 7
Then
Depreciated Value = Initial cost( 1 - percentage of depreciation) ^number of years
                              = 925( 1 - 15%)^7
                              = 925( 1 - 15/100)^7
                              = 925(1 - 0.15)^7
                              = 925(0.85)^7
                              = 925 *(0.85)^7
                              = 925 * 0.3206
                              = 296.53 dollars
So the depreciated cost of the jet ski after 7 years will be $296.53