Question

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.

Answer 1

On the 21st day, he sprints 205 yards.

Is that what you meant for the problem

or do u want to know how many yards he sprinted total for the 21 days
If it is,
he sprinted a total of 3390 yards

Answer 2

On Apex the correct one is 200 yards.