There are two drums, each containing a mixture of paints A and B. In drum 1, A and B are in the ratio 18 : 7. The mixtures from drums 1 and 2 are mixed in the ratio 3 : 4 and in this final mixture, A and B are in the ratio 13 : 7. In drum 2, then A and B were in the ratio
The correct answer is (C): Let the ratio of A and B in drum 2 be x : 1 Applying alligation, 13/20-x/x+1 = 3/4 ⇒ 13/20-x/x+1 = 3/4×72-65/100 = 21/400 ⇒ x/25-13/20 = 13/20 - 21/400 = 239/400 ⇒ 400x = 239x + 239 x = 239/161 Required ratio is 239 : 161.