If a: b = 1:4, b:c = 13:9, c:d = 5:13, find a:d?  Choose the most appropriate option
A) 5/46 B) 7/36 C) 1/36 D) 5/36 E) 5/37
a/d = (1/4)*(13/9)*(5/13) =&gt; 5/36   ANSWER:5/36
<result>D</result>
If a: b = 1:4, b:c = 13:9, c:d = 5:13, find a:d?