She can solve 75 questions per hour.
Solution:
Given that, a lady can solve 100 math problems every 4/3 hours.
We have to find how many math problems does she can solve per hour?
Now, according to the given information.
In
hours ⇒ 100 problems
Then, 1 hour ⇒ "n" problems
So, by chris cross method.
Hence, she can solve 75 questions per hour.