Answer :
Sir Isaac Newton
has shown us, in his Universal
Arithmetic, that we may
divide the bullocks in each case in two parts—one part to eat
the
increase, and the other the accumulated grass.
The first will vary
directly as the size of the field, and will not depend on the time; the
second part will also vary directly as the size of the field, and in
addition inversely with the time.
We find from the farmer's statements
that 6 bullocks keep down the growth in a 10acre field, and 6 bullocks
eat the grass on 10 acres in 16 weeks.
Therefore, if 6 bullocks keep
down
the growth on 10 acres, 24 will keep down the growth on 40 acres.
Again, we find that
if 6 bullocks eat the
accumulated grass on
10 acres
in 16 weeks, then
12 
eat
the 
grass
on 
10 
acres
in 
8 
weeks, 
48 
" 
" 
40 
" 
8 
" 
192 
" 
" 
40 
" 
2 
" 
64 
" 
" 
40 
" 
6 
" 
Add the two results
together (24 + 64), and we
find that 88
oxen may be
fed on a 40acre meadow for 6 weeks, the grass growing regularly all
the
time.
