Examination 2

A teacher awards two marks for every correct answer and subtracts a mark for every wrong answer in an examination. If there were 20 questions and a child scored 25 marks, how many correct answers did the child get?

Correct answer:

c =  15

Step-by-step explanation:

25 = 2c - 1·(20-c)

25 = 2·c - 1·(20-c)

3c = 45

c = 45/3 = 15

c = 15

Our simple equation calculator calculates it.

Did you find an error or inaccuracy? Feel free to write us. Thank you!

Tips for related online calculators
Do you have a linear equation or system of equations and looking for its solution? Or do you have a quadratic equation?

You need to know the following knowledge to solve this word math problem:

Related math problems and questions: