Question

The mean weight of 180 students in a school is 50 kg. The mean weight of boys is 60 kg and that of girls is 45 kg. Find the number of boys and girls.

Answer 1

SOLUTION:

Total student's in class =180

Mean weight=50kg

Total weight=180×50=9000kg.

Let the total no. of boys=x

Mean weight of boys=70x kg

Total no. of girls=Total student-Number of boys=180-x

Mean weight of girls=45kg

Total weight of girls=45×(180-x)=8100-45x kg

Total weight= weight of boys+weight of girls

9000=70x+(8100-45x)

9000=70x+8100-45x

9000-8100=70x-45x

900=25x

x=900÷25

x=36

Now, No. of boys= 36

Number of girls=180-36=144 ANS...

Answer 2

Answer:no of boys = 60

No of girls = 120

Step-by-step explanation: