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nidhis.1408
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Amount = Principal(1+r/100)^nnidhis.1408 wrote:An amount is deposited into an account accruing interest annually at a fixed percentage rate. It is valued at $900 in the third year (after interest has compounded twice), and $1080 in the fourth year (after interest has compounded three times). What is the original amount?
900 = Principal(1+r/100)^2 ................(1)
1080 = Principal(1+r/100)^3 .............. (2)
Divide (2) by (1)
1080/900 = (1+r/100)
or (1+r/100) = 1.2
Put this in 1
900 = Principal (1.2)^2
or Principal = 900/1.44 = 625 IMO












