41. On one of the three cards, the number 18 was written, on another - the number 75, and on the third - some two-digit number. If you add up all the different six-digit numbers that can be formed by arranging these cards in a row, the result is 2606058. What number is written on the third card?
41. Let the number on the third card be the one with $a$ tens and $b$ units, i.e., $\overline{a b}$. Then, by arranging the cards in a row, we can obtain the following numbers:

$\overline{1875 a b}, \overline{18 a b 75}, \overline{7518 a b}, \overline{75 a b 18}, \overline{a b 7518}, \overline{a b 1875 .}$

We can represent each of these numbers as a sum, for example, like this: $\overline{1875 a b}=$ $=180000+7500+\overline{a b}$. Then, when determining the sum of these six six-digit numbers, we get

$$
181818+181818+757575+757575+\overline{a b a b a b}+\overline{a b a b a b}
$$

or $1878786+2 \overline{a b a b a b}=2606058$, from which $\overline{a b a b a b}=363636$, and thus, $\overline{a b}=36$. Therefore, the number on the third card was 36.