Question

8 circles of diameter 1 cm are kept in a row, each circle touching its neighbours. How many paths of length $4\pi$ are possible to go from A(0,0) to B(8,0) if you're not allowed to traverse back?

• A. 128
• B. 256
• C. 240
• D. 300

Answer 1

The correct option is B 256

It should be $2^8=256$. Since, you have to travel along the semi-circles; and for each starting point, you have 2 choices.