Electric circuit questions,,, plz help me

An air bubble of volume 20 cm³ is at the bottom of a lake 40 m deep, where the temperature is 4.0°c. the bubble rises to the surface, which is at a temperature of 20°c.take the temperature of the bubble’s air to be the same as that of the surrounding water. just as the bubble reaches the surface, what is its volume?

Which planet do you think would be easiest for humans to colonize some day?

6. an article, which costs rs. 850 is sold at a profit of 6%.what is the selling price ? -a) rs.900 b) rs. 901 c) rs. 890 d) rs. 905