Question

The average weight of 17 girls in a class is 20 kg and 23 boys is 22 kg.Find the average weight of all students in the class

Answer 1

Answer:

Step-by-step explanation:

Total number of students=17+23=40

Average weight of 17 girls is 20 kg

So total weight of 17 girls is 20*17=340kg

Average weight of 23 boys is 22kg

So total weight of 23 boys is 23*22=506kg

Total weight of boys and girls is 506+340=846kg

Average weight=846÷40=21.5kg

Answer 2

Total no of girls = 17
average weight of girls = 20 kg
sum of weight of all girls = average weight x no of girls = 20 x 17 =340 kg

Total no of boys = 23
average weight of boys =22 kg
sum of weight of all boys = average weight x no of boys = 23 x 22 = 506 kg

Total weight of all class = weight of all boys + weight of all girls
= 340+506
=846kg
Average weight of all class = sum of weight of all class / no of students in all class
= 846/23+17
=846/40
21.15 kg