I need help please I don’t understand

Deshawn uses 3/4 of a box of rice to cook dinner the portion he uses weighs 12 ounces right and solve an equation to find the weight of the full box of rice

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 (%)

Could someone me with this question i’ve been stuck on it for 20 minutes