I can you help me one this one too please

8000 + 8800 + 8000 + 8 million + 80 trillion + another a katrillion equals

Acompany that manufactures and sells guitars made changes in their product range. from the start they had 20 models. then they reduced the number of models to 15. as a result, the company enjoyed a 10% increase in turnover. - how much did the stock level change? in (%)

Type the correct answer in the box. use numerals instead of words. if necessary, use / for the fraction bar.