A Christmas tree seller sold spruces for 220 Kč, pines for 250 Kč, and firs for 330 Kč. In the morning, he had the same number of spruces, firs, and pines. In the evening, he had sold all the trees and earned a total of 36000 Kč for them.

How many trees did the seller sell that day?

Hint. Count in threes.
A trio of fir, spruce, and pine saplings stood together

$$
220+250+330=800 \text { Kč. }
$$

The seller of such trios sold $36000: 800=45$ in a day.

In total, he sold $3 \cdot 45=135$ saplings.