To find the total amount of fruit Rhianna bought, you can simply add the weight of the apples and the weight of the oranges together.
Weight of apples: 24.2 kg
Weight of oranges: 0.7 kg
Total weight of fruit = Weight of apples + Weight of oranges
Total weight of fruit = 24.2 kg + 0.7 kg = 24.9 kg
So, Rhianna bought a total of 24.9 kilograms of fruit.