Sam gets $1000 dollars per month. she has to spend $20 a day on transportation, she also needs to buy groceries each week and have $30 extra spending money per week. how much money should be spent on food per day?

Sam makes 1,000 dollars every month. How much does she make per day?
1,000 ÷ 30 = $33.33/day. This is her daily budget.
Transportation cost = $20/day. 
Spending money/day = $30/week ÷ 7days/week = 4.28 /day

Daily Budget:
33.33 = transport  + spending money + groceries
33.33 = 20 + 4.28 + groceries           Subtract 24.28 from each side:
9.05 = groceries
$9.05 per day should be spent on groceries, assuming she doesn't want to save any of her income.