anshikakumar098
Answered

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.​

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 fo class=


Answer :

Answer:

   Mean marks for boys = 72

Step-by-step explanation:

We are provided with the following information:

  • Total number of boys in class = 10
  • Total number of girls in class = 20
  • Mean of marks for entire class = 60
  • Mean of marks for girls alone = 54

and we are asked to compute the mean marks for boys

We will use the formula
     Mean = Total/number of items
or, alternatively,
     Total = Mean * Number of items

Total number of students in class = 10 + 20 = 30

Mean of marks for class = 60

Total of marks for class of 30 students = 60 * 30 = 1800

Mean of girls' marks = 54

Total number of girls = 20

Total for 20 girls = 54 * 20 = 1080

Total of marks for 10 boys = Total for class - Total for girls

= 1800 - 1080

= 720

Mean marks for boys = Total for boys ÷ Number of boys

= 720/10

= 72