Let the marks of A, B and C are 10k, 12k and 15k, respectively.
Let k = 6
∴ Maximum marks of C can be = 15 x 6 = 90
So, maximum marks of B can be = 12 x 6 = 72
As the marks are fixed and they cannot exceed the maximum marks.
So, the marks of B cannot be in the range of (80 - 90) ie B cannot score above 80.
