Question 767570: matt gets 80% in a test. If he lost 15 marks. How many marks did he get?
Answer by algebrahouse.com(1659)   (Show Source):
You can put this solution on YOUR website! You need to determine what 15 is 20% of, because he lost 20% of the marks.
That will give you the total marks the test was worth.
a = pb {percent formula for any basic percent problem}
a is the part, p is the percent (as a decimal), b is the whole
15 is 20% of what number?
a = pb
15 = 0.2b {substituted values into percent formula, changing 20% to decimal form}
b = 75
The test was worth 75 marks. He lost 15.
He got 60.
For more help from me, visit: www.algebrahouse.com
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