arithmetic - the average age of class of 25 students is 24 years if the average of 5 of them is 22 years while average of another 5 is 26 years what is the average of the remaining 15 students - skillgun

Difference Total
25 Students 5 (22 Years) - 2 => -20
5 (26 Years) + 2 => +20
25(?)
Observe that 5 students have an average of 22 years (2 years below 24). While another 5 students have an average of 26 years (2 years above 24). Thus, the effect by (-2) is nullified by the effect of (+2). As such, the average of remaining 15 students would remain same as 24 years.