question for python learner

Question

which of these pairs are two things with the exact same value?

1. s[3], s[1+1+1]

2. s[0], (s+s)[0]

3. s[0]+s[1], s[0+1]

4. s[1], (s+ 'ity')[1]

5. s[-1], (s+s)[-1]

Answer 1

1, 2, 4, 5.......why do i have a feeling that this question is from a udacity course