He picks 1 2/5 kg less strawberries in the morning than in the afternoon . if sheldon picks 2 1/4 kg in the morning how many kilograms of strawberries does he pick in the afternoon

What you need to do is subtract 1 2/5 kg from 2 1/4 so first you have to find a common denominator which would be 20 so now it is 2 5/20 - 1 8/20 so now take the 2 5/20 and make it 1 25/20 - 1 8/20 which equals 17/20 kg (I hope you can understand that if you cant sorry that's what I learn how to do that)
                answer = 17/20