Answer:

0.80 Kg

Step-by-step explanation:

5kg = 250 cup cakes

let x kg = 40 cup cakes

Now, 1kg=250/5=50 cup cakes

or

10*5 cupcakes=1kg

10 cupcakes = 1 kg /5 = 0.20 kg

So, 40 cupcakes = 0.20 kg * 4 = 0.80 kg