A200 l balloon is blown up inside at 100 k. it is then taken outside in the hot sun and heated to 400k. what is the new volume?

According to Charles's Law, volume of an ideal gas is directly proportional to temperature at constant pressure,  

V₁/ T₁ = V₂/T₂

where V₁ and V₂ are the initial and final volume respectively and T₁ and T₂ are initial and final temperature respectively.  

Given, initial volume of balloon = 200 L

Initial temperature of balloon = 100 K

Final temperature of balloon = 400 K

Plugging the given data in Charles’s law we can calculate the final or new volume of the balloon,

V₂ = V₁/T₁ x T₂

      = (200 L/ 100 K) x 400 K = 800 L

the answer is a and have a great day