A family including mother, father and two adult sons decide to buy an investment property. Each child put $10,000 toward the purchase - the parents covered the remaining amount with funds borrowed from the Heloc on their primary residence. The investment property is in the parent's name. 

The home was purchased at the end of 2021. The prior owner will be renting the house through March of 2022. When the prior owner moves out, the family will renovate and sell the property. 

I am not sure how to handle the two son's investment and return. I assume the rental and the disposition will go on parent's return. Will the son's return on investment be paid in the form of interest?

Any thoughts?