Boston is $4$ hours ahead of Frankfurt and two hours behind India. X leaves Frankfurt at $06:00$ p.m. on Friday and reaches Boston the next day. After waiting there for two hours, he leaves exactly at noon and reaches India at $01:00$ a.m. On his return journey, he takes the same route as before, but halts at Boston for one hour less than his previous halt there. He then proceeds to Frankfurt.
What was X’s average speed for the entire journey?
- $170$ mph
- $180$ mph
- $165$ mph
- Insufficient data