Question

To receive Grade 'A' in a course, one must obtain an average of 90 marks or more in five examinations (each of 100 marks). If Sunita's marks in first four examinations are 87, 92, 94 and 95, find minimum marks that Sunita must obtain in fifth examination to get grade 'A' in the course.

Answer 1

Given:

Number of examinations = 5
Marks per examination = 100
Required average for Grade ‘A’ ≥ 90

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Step 1: Find minimum total marks required

Minimum total marks = 5 × 90 = 450

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Step 2: Calculate total marks obtained in first four examinations

87 + 92 + 94 + 95 = 368

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Step 3: Let marks in fifth examination be x

Total marks including fifth examination = 368 + x

For Grade ‘A’:

368 + x ≥ 450

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Step 4: Solve the inequality

x ≥ 450 − 368

x ≥ 82

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Final Answer:

The minimum marks Sunita must obtain in the fifth examination to get Grade ‘A’ is
82 marks.