When a student weighing 45 kgs left a class, the average weight of the...
Let the average weight of the 59 students be A.
Therefore, the total weight of the 59 of them will be 59 A.
The questions states that when the weight of this student who left is added, the total weight of the class
= 59A + 45
When this student is also included, the average weight decreases by 0.2 kgs.
59A + 45 / 60 = A - 0.2
⇒ 59A + 45 = 60A - 12
⇒ 45 + 12 = 60A - 59A
⇒ A = 57
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When a student weighing 45 kgs left a class, the average weight of the...
Let's solve the problem step by step:
Given:
- Initial weight of the student = 45 kg
- Number of remaining students = 59
- Increase in average weight of remaining students = 200 gms
Step 1: Calculate the total weight of the remaining students
Let the average weight of the remaining students be 'x' kg.
The total weight of the remaining students is then given by:
Total weight = x * Number of remaining students
Step 2: Calculate the total weight of all the students before the student left the class
The total weight of all the students before the student left the class is given by:
Total weight before = (x + 0.2) * (Number of remaining students + 1)
Explanation:
- The average weight of the remaining students increased by 200 gms, which is equivalent to 0.2 kg.
- Therefore, the average weight of all the students before the student left the class is (x + 0.2) kg.
Step 3: Calculate the weight of the student who left the class
The weight of the student who left the class is given by:
Weight of the student = Total weight before - Total weight of the remaining students
Step 4: Solve the equation
From step 1 and step 2, we have the equations:
Total weight = x * 59
Total weight before = (x + 0.2) * 60
Substituting the values in step 3, we get:
45 = (x + 0.2) * 60 - (x * 59)
Step 5: Solve for 'x'
45 = 60x + 12 - 59x
45 - 12 = x
33 = x
Therefore, the average weight of the remaining 59 students is 33 kg, which is equal to 33,000 gms.
When a student weighing 45 kgs left a class, the average weight of the...
Let the weight of the 59 students be x.
and let the average weight of 60 students be y.
so the first equation of avg weight formed including all the 60 students will be :
x+45/60 = y (1)
the second equation where the one person leaves the class and the avg. increases by 200 gm i.e. 0.2 kg therefore the equation will be:
x/59 = y + 0.2 (2)
On solving these equations you will get the answer as 57.
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