You can solve this by setting up a proportion. You can put the number of items correct over the total number. and substitute the unknown number with x.

=

Cross-multiply
3400 = 100x Divide both sides by 100
34 = x
40 - 34 = 6
So, Jill got
6 questions wrong.
Answer:
c
Step-by-step explanation:
It can work well here to simplify inside parentheses first.

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The correct selection is not show with your problem statement.
16.666666666667%
How much is 10 out of 60 written as a percentage? Convert fraction (ratio) 10 / 60 Answer: 16.666666666667%