Calculating Initial Red Paint Cans

A team of painters is working on a project to paint a large mural.

The ratio of the number of blue paint cans to the number of red paint cans used is 3:5. After using some paints, the team finds that all the blue cans are used and has 4 red cans left. If each blue can has 2 liters of paint and each red can has 3 liters of paint, what was the initial number of red paint cans used by the team?