If the sum of the first 40 terms of the series,
Question:

If the sum of the first 40 terms of the series, $3+4+8+9+13+14+18+19+\ldots$ is (102)m, then $\mathrm{m}$ is equal to :

1. 20

2. 5

3. 10

4. 25

Correct Option: 1

Solution: