Convert the 'three and two thirds' into thirds (top heavy fraction)
3 2/3 = 11/3
Now when you divide by a number (any number) it is the same as multiplying by its reciprocal
The reciprocal of 11/3 is 3/11 (just turn the number upside down)
So now we can answer the question:
11/12 x 3/11 = 3/12 = 1/4