Tracy's Pie Shop recently sold 15 pies, of which 3 were blackberry pies. Considering this data, how many of the next 20 pies sold should you expect to be blackberry pies?

For how answer my question this will be the last question can you answer in math subject

Ijust need to see how to do this. so you don’t have to answer all of them just a step by step explanation of one.

Abag contains 10 white golf balls and 6 striped golf balls. a golfer wants to add 112 golf balls to the bag. he wants the ratio of white to striped gold balls to remain the same. how many of each should he add?