Answer:
More than 93 marks in fifth subject.
Step-by-step explanation:
To secure A grade one must obtain an average of 90 marks or more in 5 subjects each of maximum 100 marks.
If one scored 84, 87, 95, 91 in first four subjects.
We need to find the minimum marks scored in the fifth subject to get A grade in the course. Let the marks be x.
[tex]\dfrac{84+87+95+91+x}{5}>90\\\\\dfrac{357+x}{5}>90\\\\357+x>450\\\\x>450-357\\\\x>93[/tex]
So, the score in the fifth subject to get A grade should be more than 93,
