Given a positive number N, when N is rounded by a certain method (for convenience, call it Method Y), the result is 10ⁿ if and only if n is an integer and 5×10^n-1≤N<5×10ⁿ. In a certain gas sample, there are, when rounded by Method Y, 10²¹molecules of H₂ and also 10²¹ molecules of O₂. When rounded by Method Y, what is the combined number of H₂ and O₂ molecules in the gas sample?

(1)The number of H₂ molecules and the number of O₂ molecules are each less than 3 X10²¹.

(2)The number of H₂ molecules is more than twice the number of O₂ molecules.