Question

1. if there is an intrusion of igneous rock into sedimentary rock, what is known about the relative age of the igneous rock?

the igneous rock is younger than the sedimentary rock.
the relative ages of the igneous and the sedimentary rock cannot be determined.
the igneous rock is older than the sedimentary rock.
the igneous and the sedimentary rock are the same age.

Explanation:

This follows the principle of cross-cutting relationships in geology: any rock (igneous intrusion) that cuts through an existing rock layer (sedimentary rock) must be younger than the rock it intrudes, as the sedimentary rock had to form first for the intrusion to occur.

Answer:

The igneous rock is younger than the sedimentary rock.