+0  
 
0
32
2
avatar

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 the boys

 

Please show working out!

Guest Oct 14, 2018

Best Answer 

 #1
avatar+2762 
+2

\(total_{all} = (n_{boys}+n_{girls})m_{total} = (10+20)60 = 1800 \\ total_{girls} = n_{girls}m_{girls} = 20 \times 54 = 1080 \\ total_{boys} = total_{all}-total_{girls} = 1800 - 1080 = 720\\ m_{boys} = \dfrac{total_{boys}}{n_{boys}}= \dfrac{720}{10}=72\)

 

kind of a sexist problem :P

Rom  Oct 14, 2018
 #1
avatar+2762 
+2
Best Answer

\(total_{all} = (n_{boys}+n_{girls})m_{total} = (10+20)60 = 1800 \\ total_{girls} = n_{girls}m_{girls} = 20 \times 54 = 1080 \\ total_{boys} = total_{all}-total_{girls} = 1800 - 1080 = 720\\ m_{boys} = \dfrac{total_{boys}}{n_{boys}}= \dfrac{720}{10}=72\)

 

kind of a sexist problem :P

Rom  Oct 14, 2018
 #2
avatar
0

Thanks for the answer!

Guest Oct 14, 2018

5 Online Users

avatar

New Privacy Policy

We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive information about your use of our website.
For more information: our cookie policy and privacy policy.