The top layer has 1 orange and the layer below has 4 oranges, the layer below has 9 oranges, the total number of oranges for each layer:
Layer 1 = 1 orange
Layer 2 = 4 oranges
Layer 3 = 9 oranges
Total: 14 oranges.
The number of oranges required for 10 layers can be solved using an arithmetic sequence.