Question

Find the average of first eight multiples of 11 is

Answer 1

Answer:

11*(25+1)/2 = 11*26/2 = 11*13 = 143. 11+22+33+44+55+66+77+88+99+110+121+132+143+154+165+176+187+198+209+220+231+242+253+264+275 =3575....