This Grade 3 Math Question Has Everyone Stumped

A Mother has shared this math problem that was on her 8 year old's math test; 

"Janell had 15 marbles. She lost some of them. How many does Janell have now?"

The student clearly saw the issue and only wrote a "?".  Alot of people on Reddit are saying it's 'cruel' to ask a third grader that. Others are offering solutons such as; 

 "<15,"

"some,"

and "15-x,"

 

This 3rd grade math problem... from funny