What is the next number in the series 50, 150, 70, 170, 90, 190, 110, 210, 130, ___?

What is the next number in the series
50, 150, 70, 170, 90, 190, 110, 210, 130, ___?

Solution:

50+100=150

150–80=70

70+100=170

170–80=90

90+100=190

190–80=110

110+100 =210

210–80 =130

130+100=230

Answer: 230