JEE Advanced 2020 Full Test 6 Paper 1

A 0.5mL sample of an aqueous solution containing 0.48µCi per mL of Na22 is injected into the bloodstream of an animal. After allowing sufficient time for complete circulatory mixing a 0.1mL sample of blood is removed and found to have a net activity of 444‌dpm of Na22 from this data, the blood volume of animal was found to be 60x mL. Find the value of x.