SOLUTION: on his first two social studies tests, billy made an 86 and a 93.what grade must billy make on the third test to have an average of 90 for all three test
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Question 956492: on his first two social studies tests, billy made an 86 and a 93.what grade must billy make on the third test to have an average of 90 for all three test Answer by macston(5194) (Show Source):
You can put this solution on YOUR website! To average 90 on three tests, the sum of the grades must be 3(90)=270
The sum of the first two grades is 86+93=179, so his grade on the third test must be 270-179=91. ANSWER: To have an average of 90, Billy must score 91 on the third test.
