Interest earned when a sum of Rs. $$X$$­ was invested for 3 years in scheme A at 6% S.I. => $$frac{X imes 6 imes 3}{100} = 482.40$$ => $$X = frac{482.40 imes 100}{18} = 2,680$$ => Amount invested in scheme B = $$2,680 - 680 = 2,000$$ Interest received when Rs. 2,000 was invested for 2 years in scheme B at 10% C.I. = $$2,000 [(1 + frac{10}{100})^2 - 1]$$ = $$2,000 [(frac{11}{10})^2 - 1] = 2,000 [(frac{121}{100}) - 1]$$ = $$2,000 imes frac{21}{100}$$ = $$20 imes 21$$ = Rs. $$420$$