Please help me I need it

Ashopper bought a watermelon a pack of napkins and some paper plates in his state there was no tax on food the tax rate on non-food items is 5% the total for the three items he bought was 825 before tags and he paid $0.19 in taxes how much did the watermelon cost

The distance around the lake is 2 kilometers. ifelena wants to run 14 kilometers this week, howmany laps must she run around the lake

Determine whether the set of whole numbers is closed under addition. explain why the set is or is not closed. give an example.