If the sum of the first 40 terms of the series, 3 + 4 + 8 + 9 + 13 + 14 + 18 + 19 + ... is (102)m, then m is equal to

Sum of the 40 terms of \ 3+4+8+9+13+14+18+19 ... =(3+8+13+ ... upto 20 term +[4+9+15+ ... upto 20 terms =10[\6+19 x 5\+\8+19 x 5\] =10 x 204=20 x 102

If the sum of the first 40 terms of the series, 3 + 4 +... | Sequence & Series (Mathematics)

Sum of the 40 terms of

$\\ 3+4+8+9+13+14+18+19 \ldots \\$

$=(3+8+13+\ldots$ { upto } 20 term $\\$

$+[4+9+15+\ldots$ { upto } 20 terms $\\$

$=10[\{6+19 \times 5\}+\{8+19 \times 5\}] \\$

$=10 \times 204=20 \times 102$