Correct Answer - Option 2 : 30 years
GIVEN:
Average age of family 8 years ago = 34
Present average age after marriage = 7 + old average
Member got married = 4 years ago
FORMULA USED:
Average = sum of all observations/total no of observations
CALCULATION:
Total present age of family excluding new member = (34 + 8) × 7 = 294 years
Total present age of family including new member = (34 + 7) × 8 = 328 years
Present age of new member = 328 - 294 = 34 years
Age of new member at the time of marriage = 34 - 4 = 30 years
∴ The age was 30 years at the time of marriage