Xiao Ming plans to put 1,2 When he thinks that the input is finished, the computer displays that only (n-1) numbers have been input, flat The average is 30.75, assuming that the (n-1) numbers are correctly input, the number of missing input is

Xiao Ming plans to put 1,2 When he thinks that the input is finished, the computer displays that only (n-1) numbers have been input, flat The average is 30.75, assuming that the (n-1) numbers are correctly input, the number of missing input is

If the number of underlosses is n
Then the average number of n-1 is n (n-1) / 2 / n-1 = n / 2
If the number of underlosses is 1, then the average number of n-1 is (n + 2) (n-1) / 2 / (n-1) = (n + 2) / 2
Obviously n / 2 ＜ 30.75 ＜ (n + 2) / 2
n＜61.5 ＜n+2
That is 61.5 ＞ n ＞ 59.5, so n = 60, or 61
Let X be the missing number
If n = 60,
(60 * 61 / 2 - x) / 59 = 30.75 (unqualified)
If n = 61
(61*62/2 -x)/60=30.75
1891-x=1845
x=46
46
The total number is 61, and the number of missing is 46