Question 111672
Interest (I)=Principal(P) times Rate(R) times Time(T) or I=PRT

Let P=amount invested at 2%
Then 3P=amount invested at 3%

Interest at 2% for 1 year=P*0.02*1 
Interest at 3% for 1 year=3P*0.03*1

And we are told that the sum of the above interests =$11.  So our equation to solve is:

0.02P+3P*0.03=$11 simplify

0.02P+0.09P=$11  collect like terms

0.11P=$11  divide both sides by 0.11

P=$100-----------------------amount invested at 2%

3P=3*$100=$300-----------------------------amount invested at 3%

CK

100*0.02+300*0.03=11
2+9=11
11=11


Hope this helps---ptaylor