Ann is grouping 38 rocks she can put them into group of 10 rocks or as single rocks

What is the question?

The difference between 1/2 and 1/6 is 2/6. So to write an expression we could do x divided by 2/6=2/3. So instead of a division expression, we could make that into a multiplication problem 2/6 times 2/3=x.  2/6 times 2/3= 4/18 so your answer is 4/18 or 2/9