SOLUTION: On his last test Greg answered 64 questions correctly and got 80% right. How many questions were on the test?

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Question 954896: On his last test Greg answered 64 questions correctly and got 80% right. How many questions were on the test?
Found 2 solutions by EdenWolf, MathLover1:
Answer by EdenWolf(517) About Me  (Show Source):
You can put this solution on YOUR website!
Set up a proportion.
64%2Fx=80%2F100
Cross multiply 64 and 100 to get 6,400. Divide 6,400 by 80 to get 80.
Thus, there were 80 questions on the test.

Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

if 64 questions answered correctly and got 80% right , then

80% of x is equal to 64:
%2880%2F100%29x=64
4x%2F5=64
4x=64%2A5
4x=320
x=320%2F4
x=80 => there was 80 questions on the test