1. Tardigrade
  2. Question
  3. Mathematics
  4. The mean of 10 numbers is 12.5, the mean of first six numbers is 15 and mean of last five is 10, then sixth number is

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. The mean of $10$ numbers is $12.5,$ the mean of first six numbers is $15$ and mean of last five is $10,$ then sixth number is

NTA AbhyasNTA Abhyas 2022

Solution:

Let numbers be $a_{1},a_{2},...,a_{10}\cdot \displaystyle \sum _{i = 1}^{10}a_{i}=125,\displaystyle \sum _{i = 1}^{6}a_{i}=90,\displaystyle \sum _{i = 6}^{10}a_{i}=50$
$\therefore a_{6}+125=90+50\therefore a_{6}=15$