Question

The average weight of 7 pupils in a class is 15kg. If the total weight of 4 of them is 75kg, What is the average weight of the remaining three

Answer 1

Average weight of remaining 3 pupil = 10 kg

Step-by-step explanation:

Given,Average Weight of 7 pupils = 15 kg

         Total weight of 7 pupils = 15 × 7

                                                  = 105 kg

     Weight of 4 pupils = 75 kg

Total weight of 7 pupils = Weight of 4 pupils + Weight of remaining 3                          pupils

105 kg = 75 kg + Weight of 3 pupil  

Weight of 3 pupil = 105 kg - 75 kg

                             = 30 kg

Average weight of remaining 3 pupil =$\frac{Total\ weight\ of\ remaining\ 3\ pupils}{3}$

                                           = $\frac{30}{3}$

Average weight of remaining 3 pupil = 10 kg