business math 3 problem question

Question

Country Day's scholarship fund receives a gift of $ 145000. The money is invested in stocks, bonds, and CDs. CDs pay 2 % interest, bonds pay 5.4 % interest, and stocks pay 11.1 % interest. Country day invests $ 35000 more in bonds than in CDs. If the annual income from the investments is $ 11880 , how much was invested in each vehicle?

Answer 1

Hi Angela Z.,

Let x = amt. invested in CD's

Let x + 35,000 = amt. invested in Bonds.

Let y = amt. invested in Stocks.

Then x + x + 35,000 + y = 145,000

This simplifies to: 2x + y = 110,000

And .02x + .054(x + 35,000) + .111y = 11,880

This simplifies to: .074x +.111y = 9990

You can solve these two equations how you like.

I put them into my TI-89, in matrix form.

My answers:

x = 15,000

y = 80,000

Therefore $15,000 invested in CD's, $50,000 invested in Bonds, and $80,000 invested in Stocks.

I hope this helps, Joe.