andes1, for the first Qs -
H can harvest 40 acres in 8 hrs.
So in 1hr it has harvested 5 acres.
Let K can harvest k acres/hr
So (5 + k) acres can be done by both the machines in 1 hr
(100 - 40) = 60 acres [H has already harvested 40 acres so 60 is left to harvest] should be in 60/(5 + k)
Therefore, 60/(5 + k) = 5
So k = 7
Ur second link is not working fine.

Thanks for your answer

Also I solved this point using my “educated guess” and maybe using my bizarre logic.

WE KNOW THAT AFTER 8 HOURS MACHINE H harvested 40 acres
8/40 after simplified 1/5 (5 acres x hour).

Now, we know that the total of acres is 100, then 100-40(harvested acres) = 60 acres remaining.

If the machine H harvest at the same rate, we will know that after 5 hours the total of acres harvested is 25… 1/25.
Next, 60 acres remaining- 25(acres harvested by machine h) = 35 acres which the machine k has to harvest in 5 hours…
So
35acres remaining / 5 hours = 7
Answer 7

Hey andes1, as u said -

Also I solved this point using my “educated guess” and maybe using my bizarre logic.

is alternative approach to solve this kind of problem. This u can not say as an educated guess but rather a good logic to solve this type of problem.