We assume the idea behind this problem is that both John and Kevin contribute the same amount of money towards the project. Since the total project cost was $383, they should each then contribute:

$383/2 = $191.50

that means John would still be contributing an additional amount:

$191.50 - $164. = $27.50

so Kevin would need to contribute:

$191.50 - 121 = $70.50

under these assumptions, Kevin owes John an additional $70.50