There are 10 boys and 20 girls in a class - Edexcel - GCSE Maths - Question 7 - 2017 - Paper 1
Question 7
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... show full transcript
Worked Solution & Example Answer:There are 10 boys and 20 girls in a class - Edexcel - GCSE Maths - Question 7 - 2017 - Paper 1
Step 1
Step 1: Calculate the total marks for all students
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
To find the total marks for the entire class, we use the mean for the class:
Total Marks = Mean Mark × Number of Students
There are 30 students in total (10 boys + 20 girls):
Total Marks = 60 × 30 = 1800.
Step 2
Step 2: Calculate the total marks for the girls
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
To find the total marks for the girls, we use the mean for the girls:
Total Marks for Girls = Mean Mark for Girls × Number of Girls
Total Marks for Girls = 54 × 20 = 1080.
Step 3
Step 3: Calculate the total marks for the boys
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Now, we can find the total marks for the boys by subtracting the total marks for the girls from the total marks for the class:
Total Marks for Boys = Total Marks - Total Marks for Girls
Total Marks for Boys = 1800 - 1080 = 720.
Step 4
Step 4: Calculate the mean mark for the boys
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Finally, we calculate the mean mark for the boys:
Mean Mark for Boys = Total Marks for Boys ÷ Number of Boys
