13. The table alongside, with 7 columns and infinite rows continuing downwards, is filled by inserting the natural numbers in ascending order, skipping all multiples of 5. With which number does the hundredth row end?

| 1 | 2 | 3 | 4 | 6 | 7 | 8 |
| :---: | :---: | :---: | :---: | :---: | :---: | :---: |
| 9 | 11 | 12 | 13 | 14 | 16 | 17 |
|  |  |  |  |  |  |  |
|  |  |  |  |  |  |  |
Problem 13. The correct answer is (B).

It is a matter of determining which number is written in the $n^{\circ} 700$ cell. The sequence proceeds in groups of 4 consecutive integers, in this way: $(1,2,3,4),(6,7,8,9),(11,12,13,14)$, and so on. Since $700: 4=175$, the request corresponds to determining the last number of the 175th quartet. From one quartet to the next, the last number always increases by 5 units. Therefore, the last number of the 175th quartet will be equal to $4+174 \cdot 5=874$.