The given ratios are a:b=512:103 and b:c=97:712.
To simplify a:b=512:103:
ba=3/1012/5
ba=512×310
ba=15120
ba=8
To simplify b:c=97:712:
cb=12/77/9
cb=97×127
cb=10849
To find a:c:
ca=ba×cb
ca=8×10849
ca=108392
ca=2798
Therefore, a:c=2798