Answer please !! I don’t know the last part

it would take 5 hours i think idk i'm not that good at math.can you me with my questions i need asap.

m∠5 + m∠3 = m∠1   is true.

m∠5 + m∠6 = 180 is true

m∠2 +m∠3 = m∠6   is true

m∠2 +m∠3 +m∠5 = 180   is true

it will take lin 15 minutes   to empty her hot tub