Question

In a quiz, +2 marks are given for a correct answer, -1 marks for an incorrect answer and 0 marks for not attempting a question. Radhika scored 30 marks. If she got 18 correct answers, how many questions did she attempt incorrectly?
fast

Answer 1

Answer:

6

Step-by-step explanation:

because 18 answers are correct it means she got 36 mark but she get only 30 so -1 per one incorrect answer it means 36-30=6

Answer 2

GIVEN

In the quiz,

+2 marks are awarded for correct

answer.

-1 for incorrect

0 for unattempted question

Radhika scored 30 with 18 correct answers.

TO FIND :- The number of answers she give incorrectly.

SOLUTION

Let the number of incorrect answers be y

According to the Question ,

2 × 18 + y ( - 1) = 30

=> 36 - y = 30

=> - y = 30 - 36

=> - y = -6

=> y = 6

Hence the number of Questions Radhika answered wrong is 6 (ANS)

VERIFICATION

LHS =

2 × Correct - 1 × Incorrect

= 2 × 18 - 1 × 6

= 36 - 6

= 30

= RHS

Hence the Answer is correct.