Please answer number 3. what does the y int mean in the context of this problem?

30 million years ago

By contrast, Hawaii's volcanoes emanate from a “hotspot” under the Pacific plate. The hotspot, which geologists estimate began producing the Hawaiian Islands 30 million years ago, is a plume of molten rock that rises through the mantle, the mostly solid layer between the crust and core.

Step-by-step explanation:

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