Multiple choice

The average age of 8 members of a committee is 40 years. If an old member of 55 years retires and a new member of 39 years is admitted what is the average age of the present committee? 8 सदस्यों की एक समिति की औसत आयु 40 वर्ष है। यदि एक बुजुर्ग सदस्य जिसकी उम्र 55 वर्ष है सेवानिवृत हो जाता है और एक नया सदस्य जिसकी उम्र 39 वर्ष है शामिल हो जाता है तो वर्तमान समिति की औसत आयु क्या हैं ?

  1. 39 years/वर्ष

  2. 38 years/वर्ष

  3. 36 years/वर्ष

  4. 35 years/वर्ष

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Total age of 8 members = 8 × 40 = 320 years. After replacing 55-year-old with 39-year-old, new total = 320 - 55 + 39 = 304 years. New average = 304/8 = 38 years. The average decreases by (55-39)/8 = 16/8 = 2 years.