Three containers, B, C and A, contained 247 beads. Bryan added some beads into Container B and the number of beads in Container B tripled. He took out half of the number of beads from Container C and added another 76 beads into Container A. As a result, the ratio of the number of beads in Container B, Container C and Container A became 12 : 4 : 5. What was the ratio of the number of beads in Container C to the total number of beads in Container B and Container A at first? Give the answer in its lowest term.