The average score in Mathematics of 90 students of sections A and B together is 49. The number of students in A was 25% more than that of B, and the average score of the students in B was 20% higher than that of the students in A. What is the average score of the students in A?

45

Let number of students in section B be x

Let average score of students in A be y

Number of students in section A = 125% of B = \(\frac{5}{4}\) × x

x + \(\frac{5}{4}\)x = 90

x = 40

Number of students in section A = 50

Total score of students in section B = 40 x 120% x y

Total score of students in section B = 40 x \(\frac{6y}{5}\) = 48y

Total score of all students of A and B = 90 x 49 = 4410

50y + 48y = 98y = 4410

y = 45

Average score of students in class A is 45