A total of $20,000 was invested in two certificates of deposit at simple annual interest rates of 3 percent and 6 percent, respectively. If the total interest on the two certificates was $1,440 at the end of one year, what fractional part of the $20.000 was invested at the higher rate? Pick:
A) 3/8
B) 21/25
C) 1/2
D) 3/5
E) 3/4
x * 3/100 * 1 + (20000 - x) * 8/100 * 1 = 1440   3x - 8x = 144000 - 160000   =&gt; -5x = -16000   =&gt; x = 32000   So 16800/20000 = 21/25   Answer - 21/25
<result>B</result>
A total of $20,000 was invested in two certificates of deposit at simple annual interest rates of 3 percent and 6 percent, respectively. If the total interest on the two certificates was $1,440 at the end of one year, what fractional part of the $20.000 was invested at the higher rate?