Answer:
The function is

Explanation:
Options are missing; I'll find the function of swimmer in relation to days
Topic: Arithmetic Progression
Given
First day = 10 laps
Increment = 5 laps daily
To get the function of the number of days, we make use of the arithmetic progression formula.

Where a = first term = 10 laps
n = number of days
d = common difference = 5

By Substitution

Hence, the function is

where n = number of days