Alec is doing a test of 50 questions. He gets 2 marks for every question that is correct, but loses 1 mark for every question that is wrong. Alec answers every question and scores 67 marks. How many questions did he answer correctly?
Answers
39 questions are correct
Step-by-step explanation:
no of questions=50
total marks=100
he scored=67
it don,t have any formulla u just have to try it with no more than 67 because it's his marks scored with some marks he not get because of cutting of 1 mark.i started it from 75 and solved it on 78
78÷2=39 sum correct
sum wrong 11=78-11
=67
hence the answer match 39 is the right answer
Answer:
39
Step-by-step explanation:
If you prefer to use simultaneous equations heres how:
1) x+y=50 this is because regardless of the score he has done all 50 questions
2) 2x-y =67 this is because I am treating x as a correct question worth 2 points and y as the deduction for any incorrect questions.
3) If you're doing this question you have probably learnt simultaneous equations so use this algebraic technique to solve for x (correct questions) and you should get 39