Question 882991
There is not enough information here.  You cannot "recover" that rent unless you charge a premium.
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Let's say that you normally charge $200/week for your apartment, but you'd like to attract renters by offering 2 weeks free.  
To recover that rent over the course of a year, you would need to charge {{{2/52}}} more rent.  The rent would then be 200*2/52 or $208 weekly. 
Think of it this way -- in a year, normal rent is 200*52 = $10,400
To make the same amount of rent in only 50 weeks, 10400/50= 208
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In real life, however, the incentive for two weeks' free pays for itself because the landlord will usually want a longer lease -- that means guaranteed occupancy of the apartment, a higher likelihood that the tenant will stay beyond the lease, and lower cleaning/repair expenses (there are always those expenses for new tenants even if the place is left clean.)