An interest of Rs. 8384 is received when a certain sum is invested for 4 years in scheme A which offers simple interest at 8% per annum. When the same sum of money is invested for 6 years in scheme B which also offers simple interest at a certain rate, the amount received is Rs. 39562, what is the rate of interest offered by scheme B ?

Let principal amount in both schemes = $$Rs. P$$

In scheme A, time = 4 years and rate = 8% under simple interest.

=> $$S.I. = \frac{P \times R \times T}{100}$$

=> $$8384 = \frac{P \times 8 \times 4}{100}$$

=> $$P = \frac{8384 \times 100}{32} = Rs. 26,200$$

In scheme B, time = 6 years and amount received under simple interest = Rs. 39,562

Principal amount = Rs. 26,200

Interest = 39562 - 26200 = Rs. 13,362

Let rate of interest = $$r \%$$

=> $$S.I. = \frac{P \times R \times T}{100}$$

=> $$13362 = \frac{26200 \times r \times 6}{100}$$

=> $$r = \frac{13362}{262 \times 6} = \frac{51}{6}$$

=> $$r = 8.5 \%$$