1. Yusef is building a pyramid out of playing
cards in which each level is constructed with a
triangular arrangement of 3 playing cards. He
builds a pyramid that is 8 levels tall, with 23
triangular arrangements on the bottom level,
and each
succeeding level has 1 fewer triangular
arrangements than the level below it. Part of 3
levels of the pyramid is shown below. How many
triangular arrangements are in the top level of the
pyramid?
A. 14
B. 15
C. 16
D. 30