RRB Group-D Model Paper 19 with answers for online practice

Given:
Total boys = 20
Total girls = 30
Average marks of boys = 60
Average marks of girls = 50
Concept:
Average = Total sum of marks/ Total persons
Calculation:
Sum of marks of boys = 20 × 60 ⇒ 1,200
Sum of marks of girls = 30 × 50 ⇒ 1,500
Average marks of whole class = (1,200 + 1,500)/ (20 + 30)
= 2,700/50
= 54