The individual numbers of a set are not given, but the mean and the count (how many numbers there are) are given. The student needs to work out the mean of a class if the mean of the boys and the mean of the girls are given. Similar questions appeared in the CSSE 11 plus exam in 2018, 2019, 2020, 2021, 2022 and 2023 maths papers. Suitable for all 11+ entry exams: Secondary school entrance exams, ISEB, CSSE, GL assessment, Grammar School entrance, Private schools, CEM and Bond.

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