Originally Posted by

**moshiman** Need some help with this.... Very confused...

I have a card with a value of 5 and 5 cards with a value of 10. I wish to trade my cardswith a guy for a complete set (1 to 10). However, he has some rules.

- you give him 2 cards and ask for 3 which add up to the same value as your 2 (eg. you give him 8 and 6 and ask for 7, a 4 and a 3 or two 5's and a 4.)

- you cannot ask for a card with a higher value than the best one you gave him (eg. he won't trade your two 9's for a 10,6 and 2)

- He never does a two for one swap (eg. if you give him a 9, he won't give you a 7 and a 2 - this is not gonna happen)

- You can't sacm him either, by trying to give him a 9 and a 6 for a 7, a 6 and a 2.

Somehow, I managed to get acomplete set thorugh trading alone.

a) Explain why I could not have done this if i had only four 10's, a 9 and a 5 to start with.