Answer: Student B will score in the top of the class.
Explanation:
Here both the students of class A and B scored 87.
Therefore, the value of random variable for both class is, x = 87
According to the question, mean for the class A is,

And, standard deviation for class A,

Thus, the z-score for Class A,
= 9/5 = 1.8
And,
Also, mean for the class B is,

And, standard deviation for class B,

Thus, the z-score for Class B,
= 11/4 = 2.75
Thus,

Therefore, student B scored in the top 10% of their class.