The average weight of 49 students in a class is 52 kg. 5 of them whose average weight is 48 kg leave...
The average weight of 49 students in a class is 52 kg. 5 of them whose average weight is 48 kg leave the class and other 5 students whose average weight is 54 kg join the class. What is the new average weight (in kg) of the class ?
Answer/Solution
52 30/49
Steps/Work
Total weight of 49 students
= 49 × 52 = 2548 kg
Total weight of 5 students who leave
= 5 × 48 = 240 kg
Total weight of 5 students who join
= 5 × 54 = 270 kg
Therefore, new total weight of 49 students
= 2548 – 240 + 270 = 2578
⇒ New average weight = 2578⁄49 = 52 30/49 kg
Answer B
= 49 × 52 = 2548 kg
Total weight of 5 students who leave
= 5 × 48 = 240 kg
Total weight of 5 students who join
= 5 × 54 = 270 kg
Therefore, new total weight of 49 students
= 2548 – 240 + 270 = 2578
⇒ New average weight = 2578⁄49 = 52 30/49 kg
Answer B