2018 · Q56
The average marks of section A are 65 and that of section B are 70. If the average marks of both the sections combined are 67, then the ratio of number of students of section A to that of section B is
Elementary MathematicsStatistics
- A3:2
- B1:3
- C3:1
- D2:3
Explanation
(65 nA + 70 nB)/(nA + nB) = 67 gives 65 nA + 70 nB = 67 nA + 67 nB, i.e. 3 nB = 2 nA. So nA:nB = 3:2. Hence option A.