"Knit gloves with 3 kilograms of wool", which should be the weight of wool woven by all gloves. Then we use 3× 3/5 = 1.8 (kg) to find out that we have used 1.8 kg of wool, and then use 1.8÷40/3=24 (double) to find out that we have knitted 24 pairs of gloves.

So the problem is solved ~ ` (* ∩ _ ∩ *)'