Let the three consecutive numbers are x, x+1, x+2

sum = 72

x + (x+1) + (x+2) = 72

3x+3 = 72

3x = 72-3

3x = 69

x = 69/3 = 23

So, the three numbers are: X = 23

x+1 = 23+1 = 24

x+2 = 23+2 = 25

So, the smallest among the three is x which is equal to 23