A married couple and a friend are sharing a cab. How much does each pay?

I think the married couple should pay 2/3 and the friend 1/3.

I agree! But the husband didn't let me! He said they were taking the cab anyway and paid full.

It's so nice to be generous on your father-in-law's dollar.

How do you know it was his F-I-L's?

Because he gets all his money from his father-in-law. It's not a secret.

This individual, or are you making an assumption about all kollel couples?

The couple pays 50% and the friend pays 50% - a husband and wife are considered as one body.

This individual.

(Though similar situations regarding kollel couples in general are certainly not uncommon.)

Who said anything about Kollel

Really? The money I spend comes out of my own pocket and if I was already going somewhere and someone joined in I wouldn't ask them to pay.

What if the couple has a small child. For those that determined that the couple should count as two people, how old does the child have to be before it is considered a 4 way split?

At first, I thought 2/3 and 1/3...but then I thought into it more, and 1/2 1/2 makes sense if the couple is sharing a bank account.
If the 2 of them would have paid one lump sum, and not split it between them, adding in another party now makes it 2 entities benefitting....

What does sharing bank accounts have to do with being counted as 1 person? So if the couple has seperate bank accounts that means they pay 2/3?
It's unfair for the single person to have to pay half.

What I meant by that is that if the husband and wife were taking a cab on their own and would have split the bill, then it's fair to split it a third way. But if they wouldn't have, and it would have been one lump payment, there is one additional party to pay, so you split it by what existed + what is now there == 2 ways.
It's better than the single person having to take his own cab.

What if they are strangers sharing a cab? Why would sharing a bank account matter in that circumstance?

Wc=combined weight of the couple
Wf=friend's weight
D=Total distance of the car ride
Dx=Total extra distance travelled to the first party's (to get off) destination as opposed to a direct route to the other party's destination would have taken.
F=Total fare

Assuming the friend got off first:

     F*D*(Wc+Wf)*i
________________
(Wc-Wf)*(D-Dx)+(π^F)

would be the amount paid by the couple...
the remainder would be paid by the friend.

Does this settle it?

If the 2 original people were each intending on splitting the cost, then there were 2 parts.
Along comes the friend == 3 parts.

With a married couple, there was only one part. The friend adds a second.

If a married couple is so particular to pay Dutch, then it would be the same as the first scenario.

No, how does "i" factor in here???

Married people aren't parts, they're people.

not true in this country, if you have 3 ppl, you pay more.

Only if you're an American fryer...

I included an imaginary number to remind people to also pay for their imaginary friends sharing the cab.

Multiply the whole thing by avocado's number and divide by the speed of light, and you have your answer.

Right (thanx for reminding me)

I was just about to bring up this point. (I think it's 3 people regular price, 4 people an added charge.) It doesn't make a difference to the driver if the 4th person is the spouse or if the 4th person is another separate entity. I still hold 2/3 couple 1/3 friend.

But 3 and under it's the same amount, right? So no one person is adding to the tab.

I think it's 3.

In that case, wouldn't it be similar to a couch that can hold 2, but a 3rd person comes on and breaks it? Isn't that guy responsible? So shouldn't the additional fee be the extra person's charge?

Right. Now let's say there are 4 people in the cab - a couple and two individuals. Is the total split 3 ways or 4?

What if there are two men in the cab and one woman, and the men tell the woman that they are a gay couple, and therefore instead of the two of them paying 2/3 of the fare, they only want to pay 1/2 the fare?

What if the couple was taking their late pet hampster for burial and the singles were coming along  to go to the levaya? What if the woman from the couple was nursing her baby? Would it make any difference if the cab ran on breast milk? Or if the dead hampster really stunk?

I think the couple should offer to pay 2/3 of the price and the single individual should offer to pay 1/2 price, and the poorer of the two entities should give in.

And what if this is a hansom cab in pre-Civil War Atlanta and one of the passengers is a slave. Does he only have to pay 3/5ths of what other people pay?

(Sorry.)

I say the tab without the extra is split either 3 or 4 ways, and the 4th person pays the extra if he joined the cab and wasn't part of the original cab-getters. (If he was, split it 3 or 4 ways, depending on what you decide about the couple.)
Now, I know in reality no one will agree to this, and l'maisah I probably would just go along with whatever said, but I know in halacha if 5 guys sit on a bench and another comes along and causes it to break, that newcomer is solely responsible for the damage. I don't know if you can apply the halachos of nezikin here, but I am trying to give a different perspective. I've recently read some fascinating cases where what I think would be the fair way for money halachically is not the right way.