Ahelium balloon is filled in a store at room temperature (24°c) to a volume of 6.5 l. the balloon is then taken outside where the temperature is only 8°c. what is the new volume of the balloon? 6.1 l 6.9 l 2.2 l 19 l

Applying Charles' Law, in which as volume increases, temperature increases and as it decreases, the temperature also decreases. Hence, 


note: Temperature in Celsius shall be converted to Kelvin

Simplifying:


x = { 6.5 (281) } / 297 
x = 6.1 L

Ohm's law tells you that i = v/r where v is equivalent voltage and r is equivalent resistance of the circuit
since all circuits have the same voltage, your question is really asking which circuit has the lowest total resistance, since the lower the resistance, the higher the current
circuit a has a resistance of 5 ohms; circuit c is in series so has a resistance of 10 ohms; circuit b is in parallel and therefore has a resistance of 2.5 ohms (review your notes on adding resistances in parallel and series); therefore b has the highest current