Question

In a class test (+4) marks are given for every correct answer and (-2) for every incorrect answers. Sana answered all the questions and scored 20 marks though she got 10 correct answers. Find the number of incorrect answers she attempted?.​

Answer 1

Answer:

She attempted 10 questions incorrectly.

Step-by-step explanation:

Let the number of incorrect answers be x.

(4 × 10) + (-2 × x) = 20

40 - 2x = 20

2x = 20

x = 10

Answer 2

Answer:

The incorrect answers given are 10.

Step-by-step explanation:

Given :

• Total marks for correct answer = 4
• Total marks deducted for each incorrect answer = 2
• Correct answer given by Sana = 10
• Sana scored = 20 marks

To find :

• The number of incorrect answers she attempted

Solution :

Sana got 10 correct answers. She had got 10 (4) = 10 × 4 = 40 marks (before reduced)

Let,

Incorrect answers = x

Marks reduced for incorrect answers = x (-2)

★ According to the Question :

$\longrightarrow$ 10 (4) + x (-2) = 20

$\longrightarrow$ 40 + - 2x = 20

$\longrightarrow$ 40 - 20 = 2x

$\longrightarrow$ 20 = 2x

$\longrightarrow$ x = 20 / 2

$\longrightarrow$ x = 10

No. of Incorrect answers = 10

∴ The incorrect answers given are 10.