Lily bought a Russian nesting doll as a souvenir. The biggest doll is 243 cm tall, and each doll is 2/3rd the size of the doll that contains it. How big is the 6th biggest doll? Let's think first. Chain of thought:
First find the size of the second - biggest doll: 243 cm * 2 / 3 = 162 cm. Then find the size of the third - biggest doll: 162 cm * 2 / 3 = 108 cm. Then find the size of the fourth - biggest doll: 108 cm * 2 / 3 = 72 cm. Then find the size of the fifth - biggest doll: 72 cm * 2 / 3 = 48 cm. Then find the size of the sixth - biggest doll: 48 cm * 2 / 3 = 32 cm.
Therefore, the answer is 32.