Raymond scored 60,72 and84marks in previous tests. If he wants to get an average mark at least 75among the four tests, what is the lowest mark hat he has to score in the coming test?
[anverage mark=total marks of the tests/number of tests]
f.2 maths 1題20分
2008-02-27 5:22 am
回答 (4)
2008-02-27 5:33 am
✔ 最佳答案
Let the Lowest Mark Of The Fourth Test Be Y.(60 72 84 Y)÷4=75
60 72 84 Y=75x4
60 72 84 Y=300
Y=300-60-72-84
Y=84
The Lowest Mark Of The Fourth Test Is 84.
(60 72 84 84)÷4=75
參考: 我
2008-02-27 5:31 am
Let x be the lowest marks that he has to score in the coming test.
60+72+84+x
--------------- = 75
4
216+x
------------ = 75
4
216+x= 300
x = 84
.
. . He has to score 84marks in the coming test.
60+72+84+x
--------------- = 75
4
216+x
------------ = 75
4
216+x= 300
x = 84
.
. . He has to score 84marks in the coming test.
參考: ME...
2008-02-27 5:29 am
Let the lowest mark in the coming test be x
(60+72+84+x) / 4 = 75
216 + x = 75 * 4
x = 300 - 216 = 84
The lowest mark to get an average mark of 75 in 4 tests in the coming test is 84.
(60+72+84+x) / 4 = 75
216 + x = 75 * 4
x = 300 - 216 = 84
The lowest mark to get an average mark of 75 in 4 tests in the coming test is 84.
參考: me
2008-02-27 5:27 am
75=(60+72+84+y)/4
75x4=lowest total mark for average 75
total minus the first three test...
equals the lowest mark for final test
75x4=lowest total mark for average 75
total minus the first three test...
equals the lowest mark for final test
收錄日期: 2021-04-13 16:27:40
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