There are 10 boys and 20 girls in a class. The class has a test. The mean mark for all the class is 60. The mean mark for the girls is 54. Work out the mean mark for the boys.

Question: There are 10 boys and 20 girls in a class. The class has a test. The mean mark for all the class is 60. The mean mark for the girls is 54. Work out the mean mark for the boys.Answer: total mark for the class= mean mark of the class multiplied by the number of students= 60 times 30=1800,total marks for girls= 54 times 20=1080, total marks for boys= total mark for class take away total mark for girls=1800-1080=720. mean mark for the boys= total marks for boys divided by the number of boys=720/10=72