Question

can anyone give me case study question of linear equation in two variable class 9​

Answer 1

Answer:

you can refer this images

Answer 2

Case study question of linear equation in two variable class

Explanation:

CASE STUDY:

A test consists of 'True' or 'False' questions. One mark is awarded for every correct answer while 4 mark is deducted for every wrong answer. A student knew answers to some of the questions. Rest of the questions he attempted by guessing. He answered 120 questions and got 90 marks 1. If answer to all questions he attempted by guessing were wrong, then how many questions did

1. He answer correct?

2. How many questions did he guess?

3. If answer to all questions he attempted by guessing were wrong and answered 80 correctly, then how many marks he got?

4. If answer to all questions he attempted by guessing were wrong, then how many questions answered correctly to score 95 marks?

 Let the no of questions whose answer is known to the student x and questions attempted by cheating be y

$x + y = 120\\x - 1/4 y = 90$

$x = 96 and y = 24$