How much of Ag has formed on the Cu tile?
In this experiment the tile lose mass due to oxidation and dissolution as Cu dication (Cu++) and acquire mass due to the reduction and deposition of Ag.

This is what is measured by weighting before and after. 

This difference in mass correspond to 2n moles of Ag minus n moles of Cu so is just matter of solving a first degree equation. 

Quickly, without being consistent in digits and truncation., 
solving it for the current data gave about 0.6 g of Ag.

All others outcomes seems to me to assume an unlike stoichiometry or refuses perpetuating around.

A way to get into an "effective stoichiometry" of 1:1 is to consider formation of Cu+ followed by disproportionation AND assuming that all metal copper finely precipitates without depositing back to the tile from which originally came from. While, partially occurring, this scenario would explain discrepancies found performing a real experiment, it seems unlikely that is intended as to give a fixed result as for it  requires the assumption in italic above. Doing that the amount of silver is now about 1.06 g.