Question

In a competition, 5 marks are given for every correct answer, and (-2)

marks are given for every incorrect answer.
a) Rehan gets 6 correct answers and 5 incorrect answers. What is his
score?
b) Rohan scored 30 marks. If he gets 10 correct answers, how many
questions he answered incorrectly?

Answer 1

For part A:-
Rehan has 6 correct ones and 5 incorrect ones, and as mentioned correct ones are 5 marks and incorrect ones are -2 marks. Now we can basically say he has (6*5) + (5*-2) marks because we can just multiply the number of questions done with the marks it gives. Simplifying, we get 30-10=20. So he got a total of 20 marks.

For part B:-
Let’s say he got “x” questions incorrect. We know that he got 10 correct answers and 30 marks in total, so it can be written like this
(10*5) + (x*-2) = 30 Similar idea to part A. Now we simplify 50 - 2x = 30
-2x=30-50
-2x=-20
-x=-10
X=10
So Rohan got 10 questions incorrectly. Hope this helps