Help with a disagreement over a math problem answer

[pwilkerson]

My sister and I went on a trip together. We agreed to split the cost that both of us incurred less a prior amount owed for flowers by me of $150.00. I will list the way that I calculated what was owed and then how she calculated what was owed. If you could tell me which is right and why I would be eternally grateful See Below

My calculation -

My credit card bill of $1060.00 plus your credit card bill of $232.00 equals $1292.00. That leaves us both responsible for $646.00. I have $150.00 left owing to you for the flowers so that makes your share of the trip expenses $496.00.

My sisters calculation -

Your credit card bill is $1060.00/2 = $530.00, My credit card bill is $232.00 of which you owe me $116.00. You also owe $150.00 for flowers. So taking the $530.00 that I owe you and subtracting the $116.00 and the $150.00 you owe me, leaves me owing you $264.00.

Who is right? and why?

Thank you in advance

 

[DrPhil]

My sister and I went on a trip together. We agreed to split the cost that both of us incurred less a prior amount owed for flowers by me of $150.00. I will list the way that I calculated what was owed and then how she calculated what was owed. If you could tell me which is right and why I would be eternally grateful See Below

My calculation -

My credit card bill of $1060.00 plus your credit card bill of $232.00 equals $1292.00. That leaves us both responsible for $646.00. I have $150.00 left owing to you for the flowers so that makes your share of the trip expenses $496.00. YES

My sisters calculation -

Your credit card bill is $1060.00/2 = $530.00, My credit card bill is $232.00 of which you owe me $116.00. You also owe $150.00 for flowers. So taking the $530.00 that I owe you and subtracting the $116.00 and the $150.00 you owe me, leaves me owing you $264.00. YES

Who is right? and why?

Thank you in advance

Her share is $496, of which $232 is already on her card. She owes you the rest, which is ($496 - $232) = $264.

[I didn't really follow your sister's logic, but she got the right answer!]

 

[JeffM]

My sister and I went on a trip together. We agreed to split the cost that both of us incurred less a prior amount owed for flowers by me of $150.00. I will list the way that I calculated what was owed and then how she calculated what was owed. If you could tell me which is right and why I would be eternally grateful See Below

My calculation -

My credit card bill of $1060.00 plus your credit card bill of $232.00 equals $1292.00. That leaves us both responsible for $646.00. I have $150.00 left owing to you for the flowers so that makes your share of the trip expenses $496.00. That is indeed her share, but she has already paid 232 of that on HER credit card. So she owes you the difference of 264. But see below.

My sisters calculation -

Your credit card bill is $1060.00/2 = $530.00, My credit card bill is $232.00 of which you owe me $116.00. You also owe $150.00 for flowers. So taking the $530.00 that I owe you and subtracting the $116.00 and the $150.00 you owe me, leaves me owing you $264.00.

Who is right? and why?

Thank you in advance

It depends on whether the flowers are on her credit card bill of 232.

If so, you are both wrong.

Your credit card = 1060
Her credit card = 232
Cost of trip plus flowers = 1292
Cost of flowers = 150
Cost of trip = 1142

Your share of trip = 571
Plus Flowers = 150
What you should pay = 721.

What you have paid = 1060
What you should pay = 721
How much you are owed = 339

Notice that her credit card bill of 232 + 339 to you adds up to 571, her half of the cost of the trip

If the flowers are not on her credit card bill of 232, then your sister is correct.

Your credit card = 1060
Her credit card = 232
Cost of trip = 1292

Your share of trip = 646
Plus Flowers = 150
What you should pay = 796.

What you have paid = 1060
What you should pay = 796
How much you are owed = 264

Notice that her credit card bill plus what she pays you = 232 + 264 = 496. What she owes is 646 - 150 = 496.

Edit: Denis introduced a new possibility, namely that the flowers are on your credit card. That generates still yet a different answer.

 

[JeffM]

Geeshhhhh...what a mess! Another go at it;
(assuming the floral 150 is not on either cards;
means the 150 has nothing to do with this):

Before doing anything, pay Sis the 150 you owe her;
she said: "....and the $150.00 you owe me..."
Now that's out of the way...

So 1060+232 = 1292, 646 each.
646 - 232 = 414 : Sis owes you.
Over and out...

This may be the simplest explanation yet. But having had a mother (that's not that unusual I admit), a sister, a wife, and a daughter, I recommend acknowledging when your sister is correct. And 414 - 150 = 264. For the sake of peace in your family, just tell your sister she is right (for once).