The mean of ten positive numbers is 16. When another number is added, the mean becomes 18. Find the eleventh number

  • A 3
  • B 16
  • C 18
  • D 38
jamb 2021mathematics

The correct answer is D. 38

The mean of ten positive numbers is 16, so the sum of these ten numbers is 10 * 16 = 160.

When another number is added, the mean becomes 18, so the sum of all eleven numbers is 11 * 18 = 198. 

Therefore, the eleventh number is 198 - 160 = 38.

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