InterviewSolution
Saved Bookmarks
| 1. |
Average marks obtained in English by 45 students in ‘A’ division are 75 and the average marks obtained by 40 students in ‘B’ division are 78. What are the overall average marks obtained in English by the students in both the divisions (rounded off to two digits of decimal)?1). 45.122). 81.233). 76.414). 89.12 |
|
Answer» We know that, formula for average: Weighted average of K groups with averages (A1, A2, A3, ………Ak)and having elements (N1, n2, n3……….nk) respectively would be given by: $({A_k} = \frac{{\LEFT( {{{\bf{n}}_1}{{\bf{A}}_1},\; + {{\bf{n}}_2}{{\bf{A}}_2} + {{\bf{n}}_3}{{\bf{A}}_3} +\ldots\ldots\ldots {{\bf{n}}_k}{{\bf{A}}_k}} \right)}}{{\left( {{n_1} + {n_2} + {n_3} +\ldots\ldots .{n_k}} \right)}})$ ∴ Required average marks = (45 × 75 + 40 × 78)/(45 + 40) = (3375 + 3120)/85 = 6495/85 = 76.41 Hence, the required average marks OBTAINED by all the students in English are 76.41. |
|