SOLUTION: for five algebra examinations, maria has an average of 88. what must she score on the sixth test to bring her average up exactly 90 ?

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Question 666442: for five algebra examinations, maria has an average of 88. what must she score on the sixth test to bring her average up exactly 90 ?
Found 2 solutions by swincher4391, DrBeeee:
Answer by swincher4391(1107) About Me  (Show Source):
You can put this solution on YOUR website!
88*5 = 440
440/500 is her score right now.
Take a test and get
440+x/600 = 90/100
600*90 = (440+x)*100
100x = 10000
x = 100
She must get a 100 to get a 90 in the class.

Answer by DrBeeee(684) About Me  (Show Source):
You can put this solution on YOUR website!
Use A = sum/6 = 90
The sum of first 5 is 5*88.
Let x = score required on sixth test.
The new sum will be 5*88 + x
The new average is new sum divided by or
(1) 90 = (5*88+x)/6 or
(2) 540 = 5*88 + x or
(3) x = 540 - 440
(4) x = 100
Answer: Maria must get 100 on the sixth exam to obtain a 90 average.
I feel bad for Maria, but at least she don't need more than 100!