name a possible set of scores for 15 students that would result in an average of 66%

66 66 66 .... 66 , (15 of those)

or

66 66 ... 65 67 .. 66 (13 of the 66's and the 65 and 67)

or how about

32 33 34 35 36 37 38 66 94 95 96 97 98 99 100