There are 100 students in a class.Number of boys is 10 more than the number of girls.The avergae weight of boys is 50kg and the avergae weight of the whole class is 45.5kg.the avergae weight of girls is?30 kg40 kg50 kg60 kg
Question
There are 100 students in a class.Number of boys is 10 more than the number of girls.The avergae weight of boys is 50kg and the avergae weight of the whole class is 45.5kg.the avergae weight of girls is?30 kg40 kg50 kg60 kg
Solution
Let's solve this step by step:
Step 1: Let's denote the number of girls as 'g'. According to the problem, the number of boys is 'g + 10'. Since the total number of students is 100, we can write the equation as: g + (g + 10) = 100.
Step 2: Solving this equation gives us g = 45. So, there are 45 girls and 55 boys in the class.
Step 3: The average weight of the whole class is 45.5 kg. This means that the total weight of the class is 45.5 kg * 100 = 4550 kg.
Step 4: The average weight of boys is 50 kg. So, the total weight of the boys is 50 kg * 55 = 2750 kg.
Step 5: The total weight of the girls can be found by subtracting the total weight of the boys from the total weight of the class: 4550 kg - 2750 kg = 1800 kg.
Step 6: Finally, the average weight of the girls can be found by dividing the total weight of the girls by the number of girls: 1800 kg / 45 = 40 kg.
So, the average weight of the girls is 40 kg.
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