There are two vessels A and B which contains mixture of sulphuric acid and nitruous oxide in the ratio of 72 and 3: 4 respectively. Mixture of both vessels are mixed to obtain a mixture of 390 ml, in which quantity of nitrous oxide is 160ml. Find ratio of quantity of mixture in vessel a quantity of mixture in vessel B? (a) 7:6 (b) 6:7 (c) 5:7 (d) 7:9 (e) 4:7