Ram invested Rs. P in scheme A and Rs. 2P in scheme B, for two years each. Scheme A offers simple interest p.a. Scheme B offers compound interest (compounded annually) at the rate of 10% p.a. The ratio between the interest earned from scheme A and that earned from scheme B was 8 : 21.

I. Rate of interest offered by scheme A.

II. Rate of interest offered by scheme C (simple interest p.a.), when Rs. 1,600 is invested for 3 years earns an interest of Rs.384.