B is directly proportional to a.
b is 10 when a is 8.
Work out b when a is 9.

45% of the trees in a park are apple trees. there are 27 apple trees in the park. how many trees are in the park in all?

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 (%)

Below are statements that can be used to prove that the triangles are similar