If \({\rm{A}} = \frac{1}{{1 \times 2}} + \frac{1}{{1 \times 4}} + \frac{1}{{2 \times 3}} + \frac{1}{{4 \times 7}} + \frac{1}{{3 \times 4}} + \frac{1}{{7 \times 10}} \ldots \) upto 20 terms, what is the value of A?
1
379/30 8
2
171/140
3
379/310
4
420/341