11-12 both xx

11. What simple interest rate r is equivalent to a simple discount rate of 9% if money is invested for 42 weeks? (A) 9.89% (B) 8.39% (C) 9.71% (D) 8.26% 12. If money doubles at a certain rate of interest compounded monthly in 6 years, how long will it take for the same amount of money to triple in value at the same interest rate? (A) 9.05 years (B) 9.51 years (C) 8.35 years (D) 10.40 years