What the names of the symbols and What do they Sells.

i believe that it is a 45% chance.

consumer credit. an advantage is that it allows consumers to afford expensive goods and services now, increasing their standard of living. however, a disadvantage is that it creates a trap for debt, if people do not have self control, they may see themselves filing personal bankruptcy.

answer: marginal utility of the fourth brownie is 0.

explanation: marginal utility is the addtional utility gained from the consumption of one more unit of a good. it is given by,

so, marginal utility at the 4th unit will be given by

since, the values are not given here, you can simply find marginal utility at fourth unit by subtracting total utility at 3rd unit from total utility at 4th unit.