Total sum of money = Rs 12,000 He invested a part of it at 5% = x He invested the other part of it at 6% = (12,000 - x) Time = 4 years SI = Rs 2,580 SI=
x×5×4
100
+
(12000−x)×6×4
100
2580=
x
5
+
72000−6x
25
x = 7,500 The sum invested at 5% per annum is Rs 7,500.