Ireally need with arithmetic problems, questions like find the “nth” term of the sequence can someone list out the formulas so i can print it out and use it?

This is the number of parts out of 100, the numerator of a fraction where the denominator is 100. submit

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 (%)

Can some one explain this i got sent this. is this a threat i’m scared