问题
单项选择题
A breakfast that consists of 1 ounce of corn puffs and 8 ounces of fruit X provides 257 calories. When 8 ounces of fruit Y is substituted for the 8 ounces of fruit X, the total number of calories is reduced to 185. If fruit X provides 1.8 times as many calories as fruit Y, how many calories does 8 ounces of fruit Y alone provide ？（）
A.11.25
B.72
C.90
D.95
E.129.6
答案
参考答案：C
解析：
设8盎斯的水果Y单独能供给x卡的热量，则8盎斯的水果X单独能供给1.8x卡的热量，根据题意可得：
1.8x-x=257-185
→x=90