Cyndee wants to invest 50000 Her financial planner advises h

Cyndee wants to invest $50,000. Her financial planner advises her to invest in three types of accounts: one paying 3%, one paying 5 1 2 %, and one paying 6% simple interest per year. Cyndee wants to put twice as much in the lowest-yielding, least-risky account as in the highest-yielding account. How much should she invest in each account to achieve a total annual return of $2120

Solution

Let she invest $x in account yielding 6%. ANd she is investing twice in lower yielding . Therefore she invests 2x yielding 3%

Therefore for 5% she invests 50000-(x+2x)=50000-3x

Let I1 is the interest earner for 3%,I2 for 5.5% and I3 for 6%

Therefore I= I1 + I2 +I3

And I=PRT

Therefore I= (x*6*1/100 ) + (2x*3*1/100)+ ((50000-3x)*1*5.5/100)

And I= 2120

2120=6x/100 +6x/100 + (50000-3x)*5.5/100

212000=6x+6x+(50000-3x)5.5

212000=12x + 275000-16.5x

-63000=-4.5x

x=14000

It means she invests $14000 with 6% ,and $28000 with 3% and 50000-3(14000)=8000 with 5.5%