Hi, I need help with this please

Let's focus now on the problem of a single agent our OLG economy. As usual, she receives an endowmenty= 5when young and nothing when old. The agent has the option to buy 2 assetsaandbin order to save for the future (there is no money). Assetaandbrates of return arera, rbrespectively. She has a typical log utility:u(c1, c2) =log(c1) +log(c2).

1. State the agent's budget constraints.
2. Suppose thatra= 2, rb= 1. What is the optimal demand for assetsaandb?
3. What is the condition onraandrbto make the agent accept to carry both assets?
4. Ifrb= 1and the agent controls the returns of assetasuch thatraa= 2a1/2, what is the the optimal demand foraandb?