Answer: The total value created from the trade is $58
Explanation: The value created by me is $25 as I sold for $70 a bicycle worth $45 to me. That is $70 - $45 = $25.
On the otherhand, my friend created a value/gain of $33. He bought the bicycle for $70 but the worth to him is $103. That is, $103 - $70 = $33
In essence, the total value created will be the summation of the value created by me and that of my friend
That is, $25 + $33 = $58