Multiple choice If a:b = 5:9 and b:c = 4:7, find a:b:c. 25:35:65 20:36:63 33:45:22 20:45:63 Reveal answer Fill a bubble to check yourself B Correct answer Explanation a:b = 5:9, b:c = 4:7. To combine, make b equal: a:b = 20:36, b:c = 36:63. Thus, a:b:c = 20:36:63.