GMS Scholars...can someone please explain the effect not having full mineral interest has on a lease bonus payment? Here's a hypothetical example-

Person signs lease based on following:

Leased Minerals - Oil and Gas

Acres - 10

Gas Royalty - 20%

Oil Royalty - 20%

Bonus Per Acre - $5,000

Expected Bonus - $5,000 X 10 = $50,000

Title examination determines person has the following mineral interest:

Oil - 8/10 = 80%

Gas - 9/10 = 90%

What should the bonus payment be considering the lease is for BOTH oil and gas? I have not received my bonus yet but I've been given the impression it will be 80% X $50,000 = $40,000.