【正确答案】 A

【答案解析】To solve this problem, you must determine the value of each quantity. Quantity A is (30% of 50)+40. Because 30% of 50 can be represented as 0.30 (50), or 15, the quantity (30% of 50)+40=15+40, or 55. Similarly, (50% of 40)+30=0.50 (40)+30, or 20+30, which equals 50. Thus, Quantity A (55) is greater than Quantity B (50).