7. An exporter of ready-made garments makes two types of shirts: X and Y. He makes a profit of Rs 10 and Rs 40 per shirt on X and Y, respectively. He has two tailors, A and B, at his disposal to stitch these shirts. Tailors A and B can devote at the most 7 hours and 15 hours per day, respectively. Both these shirts are to be stitched by both the tailors. Tailor A and Tailor B spend 2 hours and 5 hours, respectively, in stitching an X shirt and 4 hours and 3 hours, respectively, in stitching a Y shirt. How many shirts of both types should be stitched in order to maximise daily profits? (A non-integer solution for this problem will not be accepted.)