The average of nine consecutive even numbers is 24. What is the average of the smallest three of these 9 given numbers?

18

Sum of 9 even numbers = 9 × 24 = 216

Let smallest even number = a

a + (a+2) + (a+4) + (a+6) + (a+8) + (a+10) + (a+12) + (a+14) + (a+16) = 216

9a + 72 = 216

9a = 144

a = 16

Sum of three smallest even number = 16 , 18 , 20

Average = \(\frac{16 + 18 + 20 }{3}\)  = \(\frac{54}{3}\)  = 18