Question 866246
An investment firm recommends that a client should invest in bonds AAA, A and B. The average yield on AAA bonds is 6%, A bonds is 7% and B bonds is 10%. The client wants to invest twice as much in AAA bonds as B bonds. How much should be invested in each bond when:
a) The total investment is $19,000. The investor wants an annual return of $1,370. 
b) The total investment is $39,000. The investor wants an annual return of $2,810.
c=AAA

c=2b,
a+b+c=19000,
.06c+.07a+.10*b=1370

a=7000.,   b=4000.,   c=8000.

c=2b,
a+b+c=39000,
.06c+.07a+.10*b=2810

a=15000.,   b=8000.,   c=16000.