Question

Priya, Babli and Sanjay were solving problems from a problem book. Each solved exactly 60 problems, but they solved only 100 problems altogether. Any problem is known as 'easy' if it was
solved by all of them, and difficult' if it was solved by only one of them. What is the difference between the number of 'difficult problems and number of 'easy' problems?
10
20
30
40
​

Answer 1

Answer:

I think 40 or 20

I am not sure