Question

A group of pupils calculated their average score for a Mathematics

test. If one of them scored 9 marks more, their average score would
be 81. If one of them scored 3 marks less, their average score would
be 78. How many pupils were there in the group?

Answer 1

Answer: 4

Step-by-step explanation: +9-(-3)=12

81-78=3

so 12/3=4