See image — AITS & Test Series Chemistry Question

💡 Solution & Explanation

3A B t 0 a 0 t 240 hr a b b / 3     b 3b 3a a b a b 3 4 4       a a to 4  time given is 240 hours which is equal to 1/2 2t for A. Hence, 1/2 2t = 240 1/2 t 120 hrs 5 days   