In this case, according to the Avogadro's number, we take into account that for molecules such as gaseous oxygen (O₂) and nitrogen (N₂), we realize that 1 mole of these contain 6.022x10²³ moles of molecules; as we are given 1 mol each, we notice they both have 6.022x10²³ molecules, therefore, they number of molecules is the same because they have the same number of moles.
