Let total student be x ⇒ total weight of x students =x×38 ⇒38x → total students after adding 4 new =x+4 ⇒ total weight after adding 4 new weight =(x+4)×39.5 ⇒39.5x+158 According to question ⇒38x+(46+52+36+42)=39.5x+158 ⇒38x−39.5x=158−176 ⇒1.5x=18 ⇒x=12 ∴ Total number of student after adding 4 new student are 16 Average weight of new students =(46+52+36+42)∕4=44
1 unit = 4 students (new) 3 units =12 students Total =12+4=16 students