11. Three boys collectively bought a volleyball. How much money did each contribute to the purchase, if it is known that the third boy contributed 6 rubles and 40 kopecks more than the first, and $\frac{1}{2}$ of the first boy's contribution is equal to $\frac{1}{3}$ of the second boy's contribution or $\frac{1}{4}$ of the third boy's contribution?
11. 6 rub. 40 kop., 9 rub. 60 kop., 12 rub. 80 kop.