The average weight of 30 girls in a class among 50 students is 16kg and that of the remaining students is 15.5kg. What is the average weight of all the students in the class?

15.8 kg

                      Boys            Girls

                       20                30

                         2       :        3

                     15.5               16

              Avg = \(\frac{15.5 \; × \;2 + 16 \; × \; 3}{5}\) = 15.8