Question 795208: I am having trouble getting started on this problem with percentages and ratios. please help me. The word problem is: Doug, Dick, an Dean are triplets in Mr. Finch's first pd. algebra 1 class, but Friday's exam is to be their last one in that school. On the following Monday, after the triplets have left the school, Mr. Finch said the class averages. Before the triplets left the class average was 74%. However, removing their scores causes the class average to rise by 1%. Furthermore he adds, the ratios of the triplets scores is 6:5:3 What are the scores of the three departing friends? the dozen students in the class quickly arrived at a answer.
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! Doug, Dick, an Dean are triplets in Mr. Finch's first pd. algebra 1 class, but Friday's exam is to be their last one in that school.
On the following Monday, after the triplets have left the school, Mr. Finch said the class averages.
Before the triplets left the class average was 74%.
However, removing their scores causes the class average to rise by 1%.
Furthermore he adds, the ratios of the triplets scores is 6:5:3
What are the scores of the three departing friends?
:
Let x be the multiplier, then
6x, 5x, and 3x is the triplets scores
Let a = the total scores of the other student
number of remaining students = 12
:
With the triplets
 = 74
a + 14x = 15(74)
a + 14x = 1110
:
After the triplets leave
 = 75
a = 12*75
a = 900 total scores of the rest of the class
:
Find x
900 + 14x = 1110
14x = 1110 - 900
14x = 210
x = 210/14
x = 15 is the multiplier
therefore the triplet's grades
15(6) = 90
15(5} = 75
15(3) = 45
:
:
Check this
 = 74
and
 = 75
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