pls. tell me formula?

Question

for calculating land, pls. tell me how to change 2 beegha 17 biswa into acre

Answer 1

1 biswa = 1/20 bigha

1 bigha = 5/8 acre so your 2bigha 17 biswa is equal to

2 17/20 bigwa x 5/8 acre/bigwa

57/20 x 5/8 = 285/160 acre or 1.78125 acres

Answer 2

1 biswa ≈ 348480.00514077703 ft^2
1 bigha ≈ 17423.99995344307 ft^2
1 acre ≈ 43560.40063371671 ft^2

2 bigha ≈ 34847.99990688614 ft^2
17 biswa ≈ 5924160.08739321 ft^2
5959008.08730009614 ft^2 / 43560.40063371671 ft^2 =
136.79874382715600108635114312084 acre ≈
136.80 acre

If using strict scientific notation, the answer should be rounded to 100 acres.

edit:
1 biswa ≈ 20 bigha
1 biswa ≈ 8 acres
2 bigha ≈ 0.1 biswa
2 beegha 17 biswa ≈ 17.1 biswa
(17.1 biswa)(8 acres/ biswa) = 136.80 acres