If 70% of a number is equal to two-third of another number, what is the ratio of first number to the second number?  Choose the correct choice from the following options: A) 5:7 B) 18:23 C) 17:19 D) 20:21 E) 2:3
Let 70% of A = 2/3 B. Then,   70A/100 = 2B/3 =&gt; 7A/10 = 2B/3   A/B = (2/3 * 10/7) = 20/21   A:B = 20:21.   Answer: 20:21
<result>D</result>
If 70% of a number is equal to two-third of another number, what is the ratio of first number to the second number?