**A certain sum amounts to Rs 8,192 in 3.5 years and to Rs 9,472 in 6 years, at simple interest at a certain rate percent p. a. The rate of interest p.a. and the sum are ........ and ....... respectively.** A) 8.5%, Rs 6,000 B) 8.5%, Rs 6,400 C) 8%, Rs 6,400 D) 8%, Rs 6,500 Click Link for Answer