The number that is most unlike the others is 92, because all of the others are perfect squares. 7*7=79, 6*6=36, 8*8=64, 9*9=81, and 10a10=100.
But your choice of words is poor because 49, and 81 are both "odd" numbers, while the others are even.
49, 36, 25 and 64 are all squares of whole numbers. 64 = 82 49 = 72 36 = 62 25 = 52 The square root of 72 is not a whole number, but approximately 8.48. Thus 72 is the "odd one out".
Square numbers 16, 25, 36, 49, 64, 81, 100
101
Average= (36+49+64+81+100)/5 =330/5 =66
49+51=100 49 is the smaller number : P
49, 36, 25 and 64 are all squares of whole numbers. 64 = 82 49 = 72 36 = 62 25 = 52 The square root of 72 is not a whole number, but approximately 8.48. Thus 72 is the "odd one out".
Square numbers 16, 25, 36, 49, 64, 81, 100
1, 4, 9, 16, 25, 36, 49, 64, 81, 100
101
Square numbers like 1, 4, 9, 16, 25, 36, 49, 64, 81, 100
Average= (36+49+64+81+100)/5 =330/5 =66
Square numbers 1, 4, 9, 16, 25, 36, 49, 64, 81, 100
49+51=100 49 is the smaller number : P
From the first term subtract 19 to get the second, and continue to subtract the next smaller odd number to proceed down the line:100 (-19) 81 (-17) 64 (-15) 49 (-13) 36 (-11) 25 (-9) 16
.... 49, 36, 25, 16, 9, 4 and 1
The sum of 5 odd numbers must be odd and 100 is even. So there cannot be such a set.
49, 51