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.

Let us assume Sunita scored x marks in her fifth examination

Now, according to the question in order to receive A grade in the course she must have to obtain average 90 marks or more in her five examinations

∴

= 368 + x ≥ 450

= x ≥ 450 - 368

= x ≥ 82

Hence, she must have to obtain 82 or more marks in her fifth examination