Question

In a quiz, 5 marks are awarded for each correct answer and 2 marks are deducted for each wrong answer. Suppose Sam gets a correct answers and b wrong answers.

(a) Find the total marks T he gets in terms of a and b.
(b) If Sam gets 5 wrong answers and 80 marks in the quiz, find the number of correct answers Sam gets.

Answer 1

Step-by-step explanation:

let correct answers be a

for each correct answers he get 5 mark=5a

let incorrect answer be b

for each incorrect answer he get -2 mark=-2b

total mark he get is=5a-2b

(b)5 wrong answer means -2*5=10 marks

5a-2b=80

5a=80+10

5a=90

a=18

correct answer sam gets is 18

Answer 2

a) Marks for 1 correct answer = 5

Marks for 1 incorrect answer = -2

Marks for a correct answer = 5a

Marks for b incorrect answer = -2b

Total marks (T) = 5a - 2b : Ans

b) b = 5, T = 80

T = 5a - 2b

80 = 5a - 2*5

5a = 80 + 10

a = 90/5

a = 18 : Ans

Hope I helped