Which of these sentences includes an infinitive phrase? ?

400/9 weeks to empty the lake

Step-by-step explanation:

Let t = the time to empty the lake

The rate of water being released = 1/16

The rate of water being replenished = 1/25

rate times time = amount of work done

1/16(t) = the amount water that is being released

1/25(t) = the amount of water the river is putting into the lake

amount being released - amount being replenished = 1 empty lake

t/16 - t/25 = 1

25t - 16t = 16(25)

9t = 16(25)

t = 16(25)/9 =  400/9 weeks to empty the lake