X Ltd. owns all of the shares of Y Ltd. The shares of Y have an adjusted cost base of $100,000 and a fair market value of $800,000. Y has retained earnings of $400,000 (earned after 1971) and nil balances in the ERDTOH and RDTOH accounts. Y plans to pay a dividend of $500,000 to X. Subsequently, X will sell the shares of Y Ltd. to an arm's-length person for $300,000. Determine the taxable capital gain forX.

Explanations please.