please answer the following questins and show all work, thank you!

A $300 million loan commitment has an up-front fee of 25 basis points and a back-end fee of 15 basis points on the unused portion. 1. The up-front fee is 2. If 50 % of the commitment is taken down, the back-end fee is 3. If 25 % of the commitment is taken down, the total fees are 4. If 75 % of the commitment is taken down, what is the bank's rate of return on the line of credit