Question
The mean of 10 observations is 8. One more observation
is added, and the new mean becomes 9. What is the value of the 11th observation?Solution
The mean of 10 observations=18 Total =10×8=80 After including the new observations =10+1=11 New mean =11 Then total=11×9=99 13th observations =99-80 =19.
What should come in place of (?) question mark in the given number series.
81, 73, 66, 60, 55, ?
14 6 4 4 ? 48
...What should come in place of (?) question mark in the following number series.
5, 11, 23, 47, 95, ?
In each of the following number series, one term is missing. Find the missing term.
1, 4, 9, 16, 25, ?
What will come in place of the question mark (?) in the following series?
4, 11, 32, 95, 284, 851, ?
156, 182, 210, 240, 272, ?
31    32      35      ?      47       56
...What should come in place of (?) question mark in the following number series.
1, 2, 6, 24, 120, ?
What value should come in the place of (?) in the following number series?
71, 72, 76, 103, ?, 244254, ?, 1022, 1150, 1214, 1246