I don’t understand 1 2 and 3 please help

Tabby sells clothing at a retail store, and she earns a commission of 6.25% on all items she sells. last week she sold a pair of jeans for $32.50, a skirt for $18.95, and 2 blouses for $14.95 each. what was tabby's total commission? a $4.15 b $5.08 c $81.35 d $348.60

Acabinmaker buys 3.5 liters of oat varnish the varnish cost $4.95 per liter what is the total cost of 3.5 liters

Describe how making an ‘and’ compound sentence effects your solution set