ROI on Joint Venture

[Nathan Calhoun]

Hi everyone. Question- New to this and wanna do a joint venture on a flip. 

1. So...let's say home is bought at 100k.

2. Needs 100k in repairs =200k in all

3. I invest 50k which is (25%) of the total investment (200k)

4. Home sells for 300k...

Ok, so do I receive

A. 25% of my initial investment which was (50k) equaling $12,500+ $50,000 (initial investment)= $62,500 ?

B. 25% of the sales price (300k) equaling 75k + 50k (initial investment)= 125k ?

C. Are both wrong? 

Help