InterviewSolution
 Saved Bookmarks
    				| 1. | 
                                    The average score of a class of boys and girls in an examination is A. The ratio of boys and girls in the class is 3 : 1. If the average score of the boys is (A + 1), the average score of the girls is (a) (A – 1) (b) (A – 3) (c) (A +1) (d) (A + 3) | 
                            
| 
                                   
Answer»  Answer is: (b) (A – 3). Let the number of boys be 3x and the number of girls be x. Then, total number of students = 4x Average score of the class = A ∴ Total score of all the students = 4Ax Average score of all the boys = A + 1 ∴ Total score of all the boys = 3x (A + 1) = 3Ax + 3x ⇒ Total score of all the girls = 4Ax – 3Ax – 3x = Ax – 3x = (A – 3)x ⇒Average score of the girls =\(\frac{(A-3)x}{x}\) = (A – 3).  | 
                            |