Question

22. To receive Grade 24, in a course, one must obtain an average of 90 marks ormore in five examinations (each of 100 marks). If Sunita's marks in first fourexaminations are 87, 92, 94 and 95, find minimum marks that Sunita must obtairnin fifth examination to get grade A' in the course.

Answer 1

It is given that marks obtained in

1 st examination is 87, marks obtained in 2 nd examination is 92, marks obtained in 3 rd examination is 94 and marks obtained in 4 th examination is 95.

Let x be the marks obtained in 5 th examination.

So, average marks obtained by Sunita is,

Average marks= 87+92+94+95+x 5

To obtain Grade 'A', with an average of at least 90 average marks, the equation becomes,

87+92+94+95+x 5 ≥90 368+x≥450 x≥450−368 x≥82

Thus, Sunita should obtain at least 82 marks to obtain Grade 'A'.