Which payment type is best if you are trying to stick to a budget?

A debit card or cash (a debit card acts like cash pulled from your checking account) is the best payment type if you are trying to stick to a budget. This allows for only cash on hand to be used when making a purchase. Sticking to a budget is hard, but it is harder when you have access to a credit card or something that allows you to keep buying without current money on hand. Sticking to cash or a debit card helps you avoid overspending money you don’t actually have.

I believe the answer is: Debit Card

To use a debit card, you have to set aside a certain amount of money in an account, and the amount that you can used with your debit card cannot surpass the amount in the account. This would help you stick to your budget and avoid overspending.

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.