)) Two tailors, Kristen and Layla, sit down to do some embroidery. Kristen can embroider 5 shirts per hour, and Layla can get through 6 shirts per hour. In addition, the tailors had
previously finished some shirts. Kristen has already completed 15 shirts, and Layla has
completed 10 shirts. Kristen and Layla decide to take a break when they have finished the
same total number of shirts. How long will that take?