If John makes a contributino to a charity fund at school, the average contribution size will increase by 50%, reaching $75 per person. If there were 5 other contributions made before John's, what is the size of his donation?
100
150
200
250
450
averages
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This is a classic average problem where we don't know all of the individual elements, but can infer what we need from the information given.
If the new average is $75 and it is 50% more than before, it must have been $50 for the 5 people contributing before John. If the average for the 5 was 50 before John, we know they contributed 250 total irrespective of the distribution.
We'll make John's contribution x so it would be the total contributions (250+x) divided by number of contributors (6) equal to the new average (75).
(250+x)/6 = 75
x = 200, John's contribution.
If the new average is $75 and it is 50% more than before, it must have been $50 for the 5 people contributing before John. If the average for the 5 was 50 before John, we know they contributed 250 total irrespective of the distribution.
We'll make John's contribution x so it would be the total contributions (250+x) divided by number of contributors (6) equal to the new average (75).
(250+x)/6 = 75
x = 200, John's contribution.
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I go with 200..
here it is
total contribution after john = 75*6 = 450
contribution before john = 50 *5 = 250
( the average contribution size will increase by 50%, reaching $75 per person implies 75 dollars is 1.5 X. there fore X = 50)
hence john contribution = 200.
hope it helps
here it is
total contribution after john = 75*6 = 450
contribution before john = 50 *5 = 250
( the average contribution size will increase by 50%, reaching $75 per person implies 75 dollars is 1.5 X. there fore X = 50)
hence john contribution = 200.
hope it helps