Option (a) is correct

The average of six members = 30

Total age of six members = 30 * 6 = 180

when head of family is not considered members = 5 Average = 30 – 5 = 25

Total age of five members = 25 * 5 = 125

Hence the age of head of the family = 180 – 125 = 55 years.

विकल्प (a) सही है

छह सदस्यों का औसत = 30

छह सदस्यों की कुल आयु = 30 × 6 = 180

जब परिवार के मुखिया को सदस्य नहीं माना जाता है = 5 औसत = 30 – 5 = 25

पांच सदस्यों की कुल आयु = 25 × 5 = 125

अतः परिवार के मुखिया की आयु = 180 – 125 = 55 वर्ष