An amphitheatre has 24 seats in the first row, 28 in the second, 32 in the third, and so on, for 24 rows. How many seats are in the amphitheatre?

Lizette is training for a marathon. at 7: 00 she left her house and ran until 8: 30, then she walked until 11: 30. she covered a total distance of 18 miles. her running speed was six miles per hour faster than her walking speed. find her running and walking speeds in miles per hour.