- May 19, 2011
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Scenario: Joint credit card bill, my wife has gone through it to determine which transactions are for herself only (so she'll pay for those herself), and which are 'us' transactions for us to share the cost of.
Let's say the cc bill is £800, and my wife has spent £50 on herself.
Yesterday evening she boggled her own brain and gave up, then this morning showed me the two ways she could calculate it which both add up to £800 yet give different amounts for each of us to pay, and then my mind was boggled.
The way I would calculate it is this:
800 minus the "her" transaction is 750, divide 750 by 2 = 375 (my payment), then add that 50 on to her payment 375 + 50 = 425 (her payment). 375 + 425 = 800. Yay.
The way she showed me this morning:
800 / 2 = 400. Take 50 from my side and add it to her side. She pays 450, I pay 350.
I feel deep down that the solution she showed me this morning is wrong. I think it's because she's penalising herself twice for her £50 transaction, but I'm surprised that it ends up totalling to the correct amount anyway which makes me wonder whether I'm wrong even though I know perfectly well there's probably 800*800 different ways (I pulled that figure out of my ass) of adding two figures to make 800
Let's say the cc bill is £800, and my wife has spent £50 on herself.
Yesterday evening she boggled her own brain and gave up, then this morning showed me the two ways she could calculate it which both add up to £800 yet give different amounts for each of us to pay, and then my mind was boggled.
The way I would calculate it is this:
800 minus the "her" transaction is 750, divide 750 by 2 = 375 (my payment), then add that 50 on to her payment 375 + 50 = 425 (her payment). 375 + 425 = 800. Yay.
The way she showed me this morning:
800 / 2 = 400. Take 50 from my side and add it to her side. She pays 450, I pay 350.
I feel deep down that the solution she showed me this morning is wrong. I think it's because she's penalising herself twice for her £50 transaction, but I'm surprised that it ends up totalling to the correct amount anyway which makes me wonder whether I'm wrong even though I know perfectly well there's probably 800*800 different ways (I pulled that figure out of my ass) of adding two figures to make 800