please make proper calculations

Calua is an economy in which people live for three periods. They receive an endowment in only one period as follows: 80 goods when young, or 90 goods when middle-aged or 115 goods when old. The real interest rate in Calua is 10%. Given this information, what endowment should a typical person choose? Assume the interest rate increases to 15%. Which endowment should a typical person now choose