A school math contest requires that students complete all 12 problems on the contest exam. Each participant receives 5 points for each correctly solved problem and loses 3 points for each incorrect or omitted answer.
a. How many problems wer solved correctly by a student who receives a score of 36>
b. What is the minimum number of problems that participants must answer correctly to receive a positive score?
c. Provide an expression that can be used to determine the score for each participant.

I hate that I am having trouble helping my son with his math. I just can't afford a tutor. It's a shame that with all of this math that they are teaching now kids can't balance a checkbook or make change at McDonald's any more.

You can name two different variables.

x - number of correctly answers.
y - number of incorrectly/omitted answers.

The total number of problems is 12, hence, x + y = 12.

1. Then, for the marks to exceed 36, you get:

5x - 3y > 36

5x because these will sum up to the marks awarded for correct answers and -3y because this will amount up to the sum for negative marking. Solve using the two equations.

2. For this part, a positive score will be obtained when:

5x - 3y > 0

3. You should be able to guess this by now. :)

Post what you get! :)

No offense to ever tried to solve this problem, but you are way off. I have no clue what you are doing but for future references, here's the correct answer.
There is 12 questions that equal 5 points each if answered correctly, leaving you with a total of 60 possible points (5x12=60)
If a question is missed or omitted you get a penalty. Not only do you not get the 5 points but you also miss an extra 3 points added to it, which means you get a -8 points for each problem missed.
If you miss one question (60-8) you get a 52.
If you miss another questions (52-8) you get a 44.
If you miss another questions (44-8) you get a 36.
Bully made a 36, which means he missed 3 problems.
12-3=9
Bully got 9 problems correct.
You can use an actual equation here but this is better understood written out when teaching it to kids.

Quote:

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Originally Posted by kookspook

No offense to ever tried to solve this problem, but you are way off. ...

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First - this question is 2-1/2 years old, so it's way out of date.

Second - Unknown008's approach is perfectly correct. He uses a different approach than yours and he left he final steps to the OP to complete, but his method gets to the same result of there being 9 correct answers and 3 incorrect.