Josh had some marbles in his collection. He lost 6 marbles. If he has 10 marbles now How many marbles did he have in his collection?
Josh had some marbles in his collection. 

This is a given, so we'll start with that. 

Josh lost 6 marbles. 

This is also a given, so we'll take 6 away from the total number of marbles. 

If he has 10 marbles now 

This is our final answer, so we'll solve for the total number of marbles. 

How many marbles did he have in his collection?

We want to know how many marbles Josh had in his collection, so we'll solve for that. 

Josh had 16 marbles in his collection.