a)
12 months in a year
52 weeks in a year
$10 x 52 weeks = $520 for lottery tickets
$400 x 12 months = ($400 x 10) + (400 x 2) = 4000 + 800 = $4800 for rent
adding up the yearly total for both $520+$4800 = $5320
b) 4800 divided by 100 = 48 = 1% of rent
520 divided by 48 = 10.8% (11% if rounding)