Translation:There are ten toes in this woman's feet.
This woman's feet have ten toes is arguably an acceptable answer too, but I agree that 'There are ten toes on this woman's feet' is the best option. I had 'five fingers in Peter's hand' (or similar) as an English-to-Hindi translation, which did alert me to the fact that Hindi uses में for this construction, but 'in' is not correct English in this context.
Does this mean that there are 10 toes on EACH foot? I only ask because the question I got immediately before this one was the same construction, but stated that there are five fingers in Raj's hands. So either this woman has an over-abundance of toes, or Raj has lost a few fingers in his lifetime.
The explanation seems to be that whoever wrote the question and answer was not a native English speaker, and the answer was never checked by a native English speaker. And in the 5 months since people started coming across this question and commenting here, no-one has revisited this question and corrected it.
Since finishing the Hindi class, I have been doing the "Hindi to English" class, and there are examples there of incorrect answers that have existed for a couple of years. One classic has a completely different unrelated sentence given as the answer. Nearly 700 people have commented on it over the years, and no-one has ever fixed it. So I think it is a fair bet that this woman with ten toes in her feet will be here for all time.
It actually says "this woman's feet in 10 toes are". In English it would be more accurate to say "There are 10 toes ON this woman's feet".
Toes is the subject are is the verb Feet is the object of the hindi postposition in. (English preposition ON)
यह औरत के पास दस उंगली would translate to This woman has 10 toes. Woman is the subject
Hope this helps.
that would create confusion though, because पर is on, not में the point is to learn Hindi, not how to translate it into English
But word-for-word translations that retain the sense are not always possible, especially when pre/postpositions come into play, and phrases in both the target language and the language in which you learn need to make sense. The only other course I have experience with is the French course and in that case getting the sense of a phrase is definitely considered more important than a word for word translation - indeed, the latter will be marked wrong if it's not a correct construction. Sure, some people going from English to Hindi will initially attempt a direct translation and use पर instead of में, but they'll be shown the correct usage in Hindi and figure it out from there.
Even though the English sentence is not idiomatic, the method this Duo course seems to be using is an efficient way to teach the English speaker that in Hindi you say toes are IN the foot/leg. As long as we know what it means, it's instructive. Again, though, Hindi speakers who do not know English should not be trying to learn from this course.