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 m fifth examination to get grade ‘A’ in the course.

Explanation

To solve the problem step by step, we need to find the minimum marks that Sunita must obtain in her fifth examination to achieve an average of 90 marks across five examinations.

### Step 1: Understand the average requirement
To receive Grade ‘A’, Sunita must have an average of 90 marks or more in five examinations. The average is calculated by dividing the total marks obtained by the number of examinations.

### Step 2: Set up the equation for the average
Let the marks obtained in the fifth examination be \( x \). The average of the five examinations can be expressed as:
\[
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