posted by Kevin .
Bob received 6 points for each question he answered correctly on Part 1 of a test and 4 points for each question he answered correctly on Part 2. If he answered 33 questions correctly and received a total of 168 points, how many questions did he answer correctly on Part 1?
Same as the bike problem.
If he answered correctly all part 2 (4 points each) questions, then he would have got 4*33=132 points. Since he got 168 points, he got 168-132=36 points left over. Since part 1 questions has 2 points more each, he must have got 36/2=18 part 1 questions, and 33-18=15 part 2 questions.
You can also do this using system of equations if you have a pen and paper.