Question

A kind teacher gives you 20 cents for every question you get right, but you have to pay the

teacher 10 cents for every question you get wrong. After 30 questions you have made a
profit of $1.80.
a ) Form an equation with x representing the number of questions you got right.
b )Solve your equation to find how many questions you got right.

Answer 1

Let n be the number of questions you got right. Then

30-n equals the number of questions you got wrong.

So:

A) 20n-10(30-n)=180

30n-300=180

30n=480

n=16

30-n=14

B)You got 16 questions right and 14 questions wrong.