Question 1163618
jameel has a total of 3500 invested in 10%, 12% and 15% bonds.
a + b + c = 3500
 he receives the same amount of interest on the 10% bonds as on the 15% bonds.
.10a = .15c
a = .15c/.10
a = 1.5c
:
 interest on the 12% bonds is 1200. 
.12b = 1200
 b = 1200/.12
 b = 10000
A this point we know something is wrong, the total was given as only 3500
Did you mean the total is $35000???