The weight of 6 watermelons and some apples is 23 kg. The weight of each watermelon is 3 kg. What is the mass of the apples?

kg

Watermelon

The total weight of watermelons: 6 × 3 kg = 18 kg.

Apple

23 kg – 18 kg = 5 kg

The mass of the apples is 5 kg.