What is the average of all the multiples of 6 from 20 to 80?

51 50 48 52

51

From 20 to 80 , First term multiple of 6 = 24 & Last term multiple of 6 = 78 Average = \(\frac{First\; term \;+\; Last \;term }{2}\) = \(\frac{24 \;+\; 78 }{2}\) = \(\frac{102 }{2}\) = 51