Question

a layer of sandstone is in contact with a mass of granite. the sandstone contains small fragments of the granite. which rock is older?

Answer 1

The granite would be older. As millions of years go by, rocks are affected by weathering and erosion. These processes break down rocks and scatter them. Rocks are broken down into sediments, which mix with other layers, which could have been the reason how the layer of sandstone contains the small fragments of granite.