Answer :
If the remainder of the board available to Home Room 102 is 1/ 2 (or 5/10) then it follows that of the complete board the fraction used by Home room 101 is three tenths (or 3/10 ). Hope this helped answer your question!
In the question, we are told that, homeroom 101 and homeroom 102 share a bulletin board; this implies that each one of them have right to 1/2 of the bulletin board.
If homeroom 101 uses 3/5 of their half portion, then the calculation will be:
3/5 * 1/2 = 3/10.
Thus, the homeroom 101 uses 3/10 of the bulletin board to display their artwork.
