if these are numbers in a sequence 30, -10, 10/3, -10/9 what would the next 3 be?

The sequence progression is

30(-1/3)^n-1    for n = 1, 2, 3, 4......

So the next one would be

30(-1/3)^5-1  = 30(-1/3)⁴   = 30(1/81) = 30/81 = 10/27

And I'll let you do the next two....