A grocer has 400 pounds of coffee in stock, 20 percent of which is decaffeinated. If the grocer buys another 100 pounds of coffee of which 50 percent is decaffeinated, what percent, by weight, of the grocer’s stock of coffee is decaffeinated? Choose the correct choice: A) 26 % B) 30 % C) 32 % D) 34 % E) 40 %

Rationale: "1 . 20 % of 400 = 80 pounds of decaffeinated coffee 2 . 50 % of 100 = 50 pounds of decaffeinated coffee 3 . wt have 130 pounds of decaffeinated out of 500 pounds , that means 130 / 500 * 100 % = 26 % . the correct answer is a ."
Answer: A