A vessel contains equal number of moles of helium and methane. Through a small orifice the half of gas effused out. The ratio of the number of mole of helium and methane remaining in the vessel is

A vessel contains equal number of moles of helium and methane. Through

1.	A vessel contains equal number of moles of helium and methane. Through a small orifice the half of gas effused out. The ratio of the number of mole of helium and methane remaining in the vessel is
Answer» `2 :1` `1:2` `1:4` `4:1` ANSWER :B