Problema Solution

roopa patel won a prize for her work. she invested part of the money in a certificate of deposit at 4% and $3000 more than that amount in a bond paying 6%. her annual intrest income was $780. how much did roopa invest at each rate?

Answer provided by our tutors

Let x            be the amount invested on the 4% interest

     x+3000 be the amount invested on the 6% interest

      .04x + .06(x+3000) = 780

.04x + .06x + .06(3000) = 780

                     .1x + 180 = 780 

                              .1X = 600

                                 x = 600/.1

                                 x = 6000 

and 9000 for the other investment