A total of $20,000 was invested in two certificates of deposit at simple annual interest rates of 4 percent and 8 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 one: A) 3/8 B) 4/5 C) 1/2 D) 3/5 E) 3/4
x * 4/100 * 1 + (20000 - x) * 8/100 * 1 = 1440   4x - 8x = 144000 - 160000   =&gt; -4x = -16000   =&gt; x = 4000/4   So 16000/20000 = 4/5   Answer - 4/5
<result>B</result>
A total of $20,000 was invested in two certificates of deposit at simple annual interest rates of 4 percent and 8 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?