2020 · Q95
The ages of 7 family members are 2, 5, 12, 18, 38, 40 and 60 years respectively. After 5 years a new member aged x years is added. If the mean age of the family now goes up by 1.5 years, then what is the value of x?
Elementary MathematicsStatistics
- A1
- B2
- C3
- D4
Explanation
Original mean = 175/7 = 25; after 5 years the 7 members sum to 210. (210+x)/8 = 26.5 gives x = 2. Hence option (B).