Question

21.Ravi obtained 70 and 75 marks in first two unit test. Find the minimum marks heshould get in the third test to have an average of at least 60 marks.

Answer 1

It is given that Ravi obtained 70 marks in 1 st unit test and 75 marks in 2 nd unit test.

Let x be the marks obtained in 3 rd unit test.

So, average marks obtained by Ravi is,

Average marks= 70+75+x 3

To get at least 60 average marks, the above equation becomes,

70+75+x 3 ≥60

Solve for x,

70+75+x 3 ≥60 145+x≥180 x≥180−145 x≥35

Thus, Ravi should obtain at least 35 marks to have an average of 60 marks.