60. A barrel contains exactly 30 liters of linseed oil. For three construction brigades, 3 barrels were filled from it, each of which holds a whole number of liters, and the capacity of the first is $\frac{2}{3}$ of the capacity of the second or $\frac{3}{5}$ of the capacity of the third. How many liters of linseed oil are left in the barrel?
60. Let's express the capacities of the second and third buckets in terms of the capacity of the first one and schematically write it as: $\mathrm{II}=\frac{3}{2} \mathrm{I} ; \mathrm{III}=\frac{5}{3} \mathrm{I}$. Since each bucket contains a whole number of liters and the smallest number divisible by 2 and 3 is 6, the capacity of the first bucket is 6 liters, the second is 9 liters, and the third is 10 liters. Therefore, 5 liters remain in the barrel $(30-(6+9+10)=5)$.