What is the least number to be subtracted from 11, 15, 21 and 30 each so that resultant numbers become proportional? Choose the correct choice from the following answers:
A) 5
B) 6
C) 3
D) 8
E) 1
Let the least number to be subtracted be x, then 11 - x, 15 - x, 21 - x and 30 - x are in proportion.   &lt;=&gt; (11 - x) : (15 - x) = (21 - x) : (30 - x)   =&gt; (11 - x)(30 - x) = (15 - x)(21 - x)   From the options, when x = 3   =&gt; 8 * 27 = 12 * 18   Answer:3
<result>C</result>
What is the least number to be subtracted from 11, 15, 21 and 30 each so that resultant numbers become proportional?