Somebody can help me 1, 2, and 3 please

Afamily of five rents a kayak and splits the total time, k, equally. each family member spent less than 25 minutes kayaking. which values can be used to complete the math sentence below so that it accurately represents the situation? intro done

Given the equation f(x)=a(b)x where the initial value is 40 and the growth rate is 20% what is f(4)

Sum of the interior angles of a pentagon