The simple interest at the rate of 6% p.a. received on a principal of Rs. X was RS.482.40 when invested for 3 years in scheme A. If scheme…

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

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