Question 840879
let the amount invested in bonds yielding 3% be x 
then twice as much invested in bonds yielding 5% will be 2x.
the number of years is 1.
simple interest for 3% bond = (x*1*3)/100 => 3x/100
simple interest for 5% bond = (2x*1*5)/100 => 10X/100
Given that the total income of the investments was 208, then
3X/100 + 10X/100 = 208

3x+10x = 20800
13x = 20800
x=1600
therefore the money invested at 3% interest is $1,600 and money invested in 5% is 2*1600 = $3,200.