Question 133751
Interest(I) equals Principal(P) times Rate(R) times Time(T) or I=PRT

($ are understood)
Let P=amount invested in CD's @ 5%
Interest on this investment=P*0.05*1 or 0.05P

Then 130000-P=amount invested in AA bonds @ 11%
Interest on this investment=(130000-P)*0.11*1 or 0.11(130000-P)

Now we are told that the interest on these two investments needs to equal 11,900 so our equation to solve is:

0.05P+0.11(130,000-P)=11,900 simplify
0.05P+14,300-0.11P=11,900  subtract 14,300 from each side

0.05P+14,300-14,300-0.11P=11,900-14,300  collect like terms

-0.06P=-2400  divide both sides by -0.06

P=40,000 ------------amount invested on CD's at 5%

130,000-P=130,000-40,000=90,000------------amount invested in AA bonds at 11%

CK
40,000*0.05+90,000*0.11=11,900
2000+9900=11,900
11,900=11,900


Hope this helps---ptaylor