At a science competition, 25 problems were given. Each correct answer earned 4 points, and 2 points were deducted for each incorrect answer. No points were deducted for any unanswered problem. Logan answered all but one of the problems, receiving a score of 66. How many correct answers did Logan have?

Respuesta :

4*25= 100 (total points) 
x + y = 24 4x-2y = 66
since he only answered 24 questions 
therefore max he can get is 96
x + y = 24
4x-2y = 66 from first equation,
 y = 24-x plug that in second equation :
4x - 2(24-x) = 66
4x - 48 + 2x = 66 
 6x = 114
x = 19

Answer:

Correct answers of Logan is 19.

Step-by-step explanation:

Since, Logan didn't answered one problem.

Thus, total problem he attempt is 24.

Let the number of correct answer = x

and, Number of wrong answer = y

Then x + y = 24

And since it is given that,

He earned 4 points for correct answer and deduct 2 points for wrong answer. and he got score 66.

Thus we get equation,

4x - 2y = 66

Solving these two equation we get,

x = 19 and y = 6

Thus, Correct answers of Logan is 19.