Question

The average score of two sections is 28. The average score of section A is 30, in which there are 25 students. If there are 20 students in section B, then the average score of section B is

(a) 25.5 

(b) 27.5 

(c) 29 

(d) 33

Answer 1

Answer is: (a) 25.5.

Total number of students in section A and B = 25 + 20 = 45 

Average score of both the sections = 28

∴ Total score of both the sections = 28 × 45 = 1260 

Total score of section A = 25 × 30 = 750 

Let the average score of section B = x 

Then, total score of section B = 20x 

Given, 20x + 750 = 1260 

⇒ 20x = 510 ⇒ x = 25.5.