The average weight of students in sections A and B having 40 students each is 45.5kg and 44.2 kg respectively. Two students of section A having an average weight of 48.75 kg were shifted to section B and 2 students of section B were shifted to section A, making the average weight of both the section equal. What is the average weight (in kg ) of students who were shifted from section B to section A?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 35.75
Total weight of students of section A = 40 × 45.5 = 1820 kg.
Total weight of students of section B = 40 × 44.2 = 1768 kg.
The weight of two students who got shifted from A to B = 48.75 × 2 = 97.5 kg.
The weight of the students who got shifted from B to A = 2 × x = 2x
After this transfer, the average of both sections becomes the same.
(1820 - 97.5 + 2x)/40 = (1768 - 2x + 97.5)/40
1722.5 + 2x = 1865.5 - 2x
4x = 143
x = 143/4 = 35.75 kg.