43 is 10% of what number

Simplify a7/a4 a) 1/a3 b)-a/a2 c)a4/a3 d)a3

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 (%)

Eden has a part time job. she is paid ? 7.20 an hour the week she worked 18 and a half hours how much is she paid