Some female butterfly lay their eggs in clusters. if one kind of butterfly lays 12 eggs at a time and another kind lays 18 eggs at a time, how many eggs would 8 of each kinda of butterfly lay?

There are several important information's already given in the question. Based on those information's the answer to the question can be easily deduced.
Number of eggs laid down at a time by a single butterfly of one kind = 12
Then
Number of eggs laid down at a time by 8 butterflies of one kind = (12 * 8)
                                                                                                     = 96
Again
Number of eggs laid down at a time by a single butterfly of another kind = 18
Then
Number of eggs laid down at a time by 8 butterflies of another kind = (8 * 18)
                                                                                                           = 144
So the total number of eggs laid down by 8 butterflies of one kind is 96 and the total number of eggs laid down by 8 butterflies of another kind is 144. Hope this helps you.