Question

A student is taking an exam with 40 questions on it.To pass the exam she needs to answer 70% of the questions correctly. Unfortunately she answered only 40% of the 15 questions correctly. What percent of the remaining 25 questions does she have to answer correctly to pass the exam?

Answer 1

The first step is to find out how question in total she is able to miss, while still passing.

We know that there are
`40\\` questions on the test and she must get
`70`% of the questions correct.

Let's calculate how many questions that is:

40 x 0.70

= 28.

Subtract

40 - 28

= 12.

She is able to get 12 answers incorrect.

Now we must find out how many questions she got wrong when she got 40% of the first 15 correct.

If she got 40% correct; She got 60% incorrect.

Let's do the math:

Multiply:

15 x 0.40

= 6

Subtract:

15 - 6

= 9

This means that she got 6 questions correct, and 9 questions incorrect.

With the total allotment of 12 incorrect answers allowed, she can only get 3 more questions wrong.

Now we must find the percentage of the remaining 25 questions she can get wrong.

She can only get 3 wrong and she must get 22 correct.

Multiply:

22 x 4

= 88.

This means that she has to get 88% of the remaining 25 questions correct.