दहा माणसांच्या समूहातील 25 वर्षे वयाचा एक माणूस बदलून, नवीन माणूस आल्यास, दहा माणसांचे सरासरी वय पूर्वर्वीपेक्षा 2 वर्षाने वाढते तर नवीन माणसाचे वय किती ?

The correct answer is Option A (45 years).

Key Points:
• This is an average replacement problem.
• Analyzing the logic:
• Number of persons (n) = 10
• Age of the person who left = 25 years.
• The average age of all 10 persons increased by 2 years.
• Calculate the total increase in age:
• Total increase in age for the whole group = Number of persons × Increase in average
• Total increase = 10 × 2 = 20 years.
• Calculate the age of the new person:
• Age of new person = (Age of outgoing person) + (Total increase in age)
• Age of new person = 25 + 20 = 45 years.
• Therefore, the age of the new man is 45 years. Option 1 is correct.
• Key Takeaway: Age of new person = Outgoing age + (Number of persons × Increase in average) = 25 + (10 × 2) = 45 years.