Harry the Hungry Hippo is munching on the lily pads in his pond. When he got to the pond, there were $20$ lily pads, but he is eating $4$ lily pads an hour. Heinrick the Hungrier Hippo found a better pond with $29$ lily pads! He eats $7$ lily pads every hour.

1. If Harry and Heinrick start eating at the same time, when will their ponds have the same number of lily pads remaining?

   Hint (a):

   Write an equation representing each hippo.

   More Help (a):

   Set the two equations equal to each other and solve for $x$.

   Answer (a):

   $x=3\ \text{hours}$

2. How many lily pads will be left in each hole at that time?

   Hint (b):

   Substitute $3$ back into one of the original equations and solve for $y$.