Yes that answer is accurate
to do it in mental math: you can ignore the zeroes in 400 for now.
4*14 = 4*10 + 4*4 = 40 + 16 = 56
now add the zeroes back on: 5600m
The scale for the second values is 56/8 = 7
C = 3 x 7 = 21
C= 21
16/35
In 1/8 of a day they plant 2/35 of an Acre
So multiply 1/8 by 8 to get one day next do this to the rest of the problem 2/35 times 8 is 16/35 and that’s the answer