UP Police Constable Exam Model Paper 2

Given:
Average age of mother and 6 children = 12 years
When mother is excluded, average is reduced by 5 years
Formula used:
Average =(Sum of values)/(Total number of values)
Calculation:
Average when mother is excluded = 12 – 5 = 7 years
Sum of ages of mother and her 6 children = 12 × 7 = 84 years
Sum of ages of 6 children = 7 × 6 = 42 years
Age of mother = 84 – 42 = 42 years
∴The age of mother is 42 years.