Given:
Marks in first test = 70
Marks in second test = 75
Number of tests = 3
Required average ≥ 60
Step 1: Find minimum total marks required
Minimum total marks = 3 × 60 = 180
Step 2: Calculate total marks obtained in first two tests
70 + 75 = 145
Step 3: Let marks in the third test be x
Total marks = 145 + x
For the required average:
145 + x ≥ 180
Step 4: Solve the inequality
x ≥ 180 − 145
x ≥ 35
Final Answer:
The minimum marks Ravi should get in the third test to have an average of at least 60 marks is
35 marks.