Janine charges $8.25 per hour to walk dogs. She walks dogs for 3 hours on Saturday and 4 hours on Sunday. She calculates her total pay to be $57.75. Which equation could be used to check the reasonableness of her total? 8 × 7 = 56 9 × 7 = 63 10 × 7 = 70 8 × 10 = 80