A total of $20,000 was invested in two certificates of deposit at simple annual interest rates of 6 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 $20.000 was invested at the higher rate?	Choose the most appropriate option:
A) 3/8	B) 2/5	C) 1/2	D) 3/5	E) 3/4
Let "$x" be invested with the higher rate of 8%   Thus, "20000-x" must have been invested with lower rate of 6%   Simple Interest = Principal* Rate* Time   For the Amount invested at 8%   Principal = x   Rate = 0.08   Time = 1   Simple Interest = x* 0.08* 1= 0.08x   For the Amount invested at 6%   Principal = 20000-x   Rate = 0.06   Time = 1   Simple Interest = (20000-x)* 0.06* 1= 1200-0.06x   Total Interest = $1440   0.08x+1200-0.06x=1440   0.02x=240   x = 240/0.02= 
<gadget id="calculator">240/0.02</gadget>
<output>12_000</output>
12000   Fraction of x per total amount= 12000/20000 = 12/20 = 3/5   Ans: "3/5"
<result>D</result>
A total of $20,000 was invested in two certificates of deposit at simple annual interest rates of 6 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?