The repair of the wall of the room required 3.6 kg of plaster. this represents four-ninths of the plaster

The repair of the wall of the room required 3.6 kg of plaster. this represents four-ninths of the plaster allocated for the renovation. How many kg of plaster have been allocated for repairs?

Let’s designate the unknown variable as a kilogram of plaster – it was allocated for repairs.
Then 4/9 * x kilogram of plaster – it took to repair the wall of the room.
Based on the condition of the problem, we compose the equation:
4/9 * x = 3.6;
x = 8.1 kilograms of plaster – was allocated for repairs.
Answer: 8.1 kilograms of plaster were allocated for repairs.