Tenants running out of hot water?

[Paul Sandhu]

I've got 4 guys that are trying to save money, they've rented from me before.  They rented a 2 bedroom apartment.  One guy in each bedroom and the other 2 guys are sleeping on their own inflatable beds in the living room.  Problem is that it only has a 40 gallon hot water tank and they run out of hot water when they all take a shower after each other.

What would you do?

I told them to take a shower together.