Question

03. The average weight of some students in a class is 62% kg, If 8 students of average weight 55 kg leave
the class and 13 students of average weight 65 kg join has class, then the average weight of the remaining
students in the class ls 63.9 kg. The number of students in the class, initially was ______​

Answer 1

Answer:

Let there be n students in the class.

60n+64(8)=62(n+8)

62n−60n=64(8)−62(8)

2n=16

n=8

Therefore, initially there were 8 students in the class.

Answer 2

Answer:

45

Step-by-step explanation:

no of students =x

average weight of  students  = 62 kg

average  weight of 8 students =55 kg

average  weight of 13 students=65kg

total weight of 8 students = 8*55 => 440 kg

total weight of 13  students = 13*65=>845 kg

tot weight - tot weight of 8 students +tot weight of 13 students =remaining students weight total +number  of  13-8 => 5 students

62*x-440+845 = 63.9(x+5)

62*x+405=63.9*x+63.9*5          

62*x+405=63.9*x+319.5

405-319.5=63.9*x-62*x

85.5=1.9*x

x=85.5/1.9

x=45

initially students were 45