標題:
f.2 maths 20分
發問:
此文章來自奇摩知識+如有不便請留言告知
1. x is greater than y by 5, and the sum of x and y is less than 49. Find the largest value of x is an integer.2. The sum of three consecutive even numbers is greater than29. Find the least value of the smallest number.3. In a History test, 5 marks are given for wach correct answer and 2 marks are... 顯示更多 1. x is greater than y by 5, and the sum of x and y is less than 49. Find the largest value of x is an integer. 2. The sum of three consecutive even numbers is greater than29. Find the least value of the smallest number. 3. In a History test, 5 marks are given for wach correct answer and 2 marks are deducted for each incorrect answer. Roger has answered 30 questions and his score is greater than15 marks. Find the least number of number of questions he has answered correctly.
最佳解答:
(1) x-y = 5 -> x-5=y x+y x+x-5 2x-5 2x 2x x the largest value of x as an integer = 26 (2) Let the smallest even no. be x x + (x+2) + (x+4) > 29 -> 3x + 6 > 29 -> 3x > 23 -> x>7.66 -> the least value of x = 8 (3) Let the least no. of correct answers be x 5x -2(30-x) >15 -> 5x - 60 + 2x > 15 -> 7x - 60 > 15 -> 7x > 75 -> x > 10.71 -> the least number of questions he answered correctly = 10
其他解答:
peterchan7708第3題既最後答案應該係11,而唔係10
留言列表
