Ezra is training for a track race. He starts by sprinting

Last updated: 7/15/2022

Ezra is training for a track race. He starts by sprinting 100 yards. He gradually increases his distance, adding 5 yards a day for 21 days. The explicit formula that models this situation is an = 100 + (n-1)5. How far does he sprint on day 21? A. 200 yards B. 100 yards C. 225 yards D. 205 yards