Shelly was surprised to learn the dwarf planet pluto used to be considered a planet. what would have had to be true for pluto to remain categorized as a planet?

pluto would need to have an atmosphere.
pluto would need to clear the neighborhood of its orbit.
pluto would need to have a larger moon.
pluto would need to have water or ice.

Aswimming pool whose volume is 10 comma 000 gal contains water that is 0.01% chlorine. starting at tequals0, city water containing 0.003% chlorine is pumped into the pool at a rate of 5 gal/min. the pool water flows out at the same rate. what is the percentage of chlorine in the pool after 1 hour? when will the pool water be 0.006% chlorine?