Assume that for the entire business sector of the economy there is $5 worth of investment projects which yield an expected rate of return of 25 percent or more. But there are $9 worth of investments which will yield an expected rate of return of 20-25 percent; another $12 with an expected rate of return of 15-20 percent; and similarly an additional $16 of investment projects in each successive rate of return range down to an including the 0-5 percent rage. Refer to the above information. If the real interest rate is 15 percent, which amount of investment will be undertaken?