Help Me Pls Help Me Pls

Jamie went to home depot.she bought 25 bags of soil that cost $9 per bag.she bought 15 pots at $8 each, and she bought 23 bags of pebbles at $15 each.she used a coupon that gave her $5 off for every 100 dollars she spent. how much did jamie pay at the end?

The radius of the earth is two times the radius of the moon. what fraction of the volume of the earth is the volume of the moon?

Math i have no idea how to do a and b