问题
单项选择题
A farmer with 1,350 acres of land had planted his fields with corn, sugar cane, and tobacco in the ratio of 5:3:1, respectively, but he wanted to make more money, so he shifted the ratio to 2:4:3, respectively. How many more acres of land were planted with tobacco under the new system ？（）
A. 90
B. 150
C. 270
D. 300
E. 450
答案
参考答案：D
解析：
The numbers in both sets of ratios add up to 9, so you can look at each of the ratios in terms of ninths of 1,350. In the original planting system, tobacco accounted for 1/9 of the total, so 1,350/9=150. In the new system, tobacco accounts for 3/9, or 450. 450-150=300.