Question 21 of 40intermediate🔧 ApplyNumerical4 marks

Ravi obtained 70 and 75 marks in first two unit test. Find the minimum marks he should get in the third test to have an average of at least 60 marks.

Correct Answer

Ravi should get a minimum of 35 marks in the third test to have an average of at least 60 marks.

Exercise: EXERCISE 5.1 | Q: 21 | (Page Page 8)
For More Understanding

Explanation

This question is from Linear Inequalities chapter. The solution follows the same pattern as Example 7 in the textbook, where a similar problem is solved. The key concept is setting up an inequality for the average marks and solving for the unknown marks.

Solution Steps

  1. Step 1: Let x be the marks obtained by Ravi in the third unit test.

  2. Step 2: Calculate the average of marks in three tests: Average = (70 + 75 + x)/3

  3. Step 3: Set up the inequality for average to be at least 60 marks: (70 + 75 + x)/3 ≥\geq 60

  4. Step 4: Multiply both sides by 3: 70 + 75 + x ≥\geq 180

  5. Step 5: Simplify: 145 + x ≥\geq 180

  6. Step 6: Solve for x: x ≥\geq 180 - 145, therefore x ≥\geq 35

  7. Step 7: Hence, the minimum marks required in the third test is 35 marks.

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