greWhen9studentstookazoologyquizwithapossiblescoreof0to10inclusive,theiraveragescorewas7.5.Ifatenthstudenttakesthesamequiz,whatwillbetheleastpossibleaveragescoreonthequizforall10students.A.6.5B6.75C.7.0D7.25

Question

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When 9 students took a zoology quiz with a possible score of 0 to 10 inclusive,their average score was 7.5.If a tenth student takes the same quiz,what will be the least possibleaverage score on the quiz for all 10 students.A.6.5 B6.75 C.7.0 D7.25 E7.5
A certain doctor suggest that individual's daily water intake be 0.5 ounce per pound of body weight plus 8 ounces for every 25 pounds by which the individual exceeds his or her ideal weight.If this doctor suggest a daily water intake of 136ounces for a particular 240-pound individual,how many pounds abovehis or her ideal weight is that individual?
A12.5 B16 C30 D50 E120

Answer 1

第一题,题目说原来有9个学生参加测试,测试分数从0分到10分,他们的平均分是7.5,后来第10个学生加进来,问10个学生可能的最低的平均分是多少?
答案是B,最低平均分出现在第十个学生得0分的时候,这时最低平均分为(9*7.5+0)/10=6.75.
第二题,题目说医生建议个人每日饮水量为：0.5 ounce/pound 乘以个人体重,加上 8 ounce 每 25 pounds 乘以个人体重超出标准体重的部分.现在医生建议某人每日饮水136 ounces,而这个人的体重是240 pound.问这个人体重超出标准体重多少?
答案是D,假设超出部分的重量为x,列方程：0.5*240+8*x/25=136,解得x=50.