A fruit and vegetable merchant installed 15 kg of carrots, 13 kg of zucchini and 8 kg of broccoli. He sold only half of them. What mass of vegetables did he sell?
You first need to know the total weight of the vegetables, so you add each quantity: 15 + 13 + 8 = <<15+13+8=36>>36 kg
Then you have to find half of 36: 36/2 = <<36/2=18>>18 kg.
So, he sold 18 kg of vegetables.
#### 18