In the given ratios "B" is the
common term, and the values of B in both ratios are not equal. To make them
equal, find the L.C.M. of values corresponding to B i.e., 4 and 6.
L.C.M. of 4 and 6=12
Therefore, an equivalent ratio of A:B=3:4=3×3:4×3=9:12
Similarly, an equivalent ratio of B:C=6:7=6×2:7×2=12:14
Therefore,A:B:C=9:12:14