Josh had some marbles in his collection. He lost 47 marbles. If he has 1 marbles now How many marbles did he have in his collection?
Josh had some marbles in his collection. 

That means that at some point in time, he had more than one marble. 

He lost 47 marbles. 

That means that at some point in time, he had 47 more marbles than he does now. 

If he has 1 marble now, 

That means that at this point in time, he has 48 less marbles than he did at the previous point in time. 

So, if he lost 47 marbles and has 1 marble now, he must have had 48 marbles at some point in the past.