Question
The total number of students in class A is 112, and the
ratio of girls to boys is 7:9. If the average number of boys in classes A and B is 162, and the average number of girls in classes A and B is 114, find the total number of students in class B.Solution
Number of girls in class A = (7/16) × 112 = 49
Number of boys in class A = (9/16) × 112 = 63
Number of boys in class B = 162 × 2 - 63 = 324 - 63 = 261
Number of girls in class B = 114 × 2 - 49 = 228 - 49 = 179
Total number of students in class B = 261 + 179 = 440
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