10. The table alongside, with 7 columns and infinitely many rows extending downwards, is filled by inserting the natural numbers in ascending order, skipping all multiples of 5. With which number does the 120th row end?

| 1 | 2 | 3 | 4 | 6 | 7 | 8 |
| :---: | :---: | :---: | :---: | :---: | :---: | :---: |
| 9 | 11 | 12 | 13 | 14 | 16 | 17 |
|  |  |  |  |  |  |  |

(A) 1049
(B) 1051
(C) 1052
(D) 839
(E) 841
Problem 10. The correct answer is $\mathbf{( A )}$.

The task is to determine which number is written in the $\mathrm{n}^{\circ} 840$ cell. The sequence proceeds in groups of 4 consecutive integers, as follows: $(1,2,3,4),(6,7,8,9),(11,12,13,14)$, and so on. Since $840: 4=210$, the request corresponds to determining the last number of the 210th quartet. From one quartet to the next, the last number always increases by 5 units. Therefore, the last number of the 210th quartet will be equal to $4+209 \cdot 5=1049$.