问题
单项选择题
A restaurant orders 150 kg of pumpkins from the farmer’s market. The farmer fills the order with 23 pumpkins. The average mass of the first 20 pumpkins is 6.5 kg. What must be the minimum average mass of the remaining 3 pumpkins to fill the order ？（）
A. 5.5 kg
B. 5.67 kg
C. 6.67 kg
D. 7 kg
E. 11.5 kg
答案
参考答案：C
解析：
The remaining three pumpkins must make up the difference between 150 kg and (20 pumpkins×6.5kg=)130 kg, so 20 kg. For three pumpkins to fill 20 kg, each must have a minimum mass of 2O kg divided by 3, which equals 6 2/3 kg, which is best expressed here as 6.67 kg.