The average weight of 46 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 ?  Choose the most appropriate option:
A) 51 1⁄23
B) 52 15/23
C) 52 15⁄3
D) 43.42
E) None of these
Total weight of 46 students   = 46 × 52 = 2392 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 46 students   = 2392 – 240 + 270 = 2422   ⇒ New average weight = 2422⁄46 = 52 15/23 kg   Answer 52 15/23
<result>B</result>
The average weight of 46 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 ?