What mountains did westbound silk road travelers have to cross before reaching marakanda?

They would have to cross the Himalayas, Karakorum, and Kunlun mountain ranges. 

Himalayas, Karakorum, and Kunlun ranges.

Explanation:

The silk route travelers connected the east Asia with southeast Asia.With Persia and the Arabian peninsula.  And it began with the Han dynasty in China. And it expanded to central Asia and thus they extended the great wall of china to protect the trade route. The northern route included many mountainous ranges like the china, Kazakhstan and Afghanistan. The Himalayas in the India and the southern route was of the Karakorum ranges and Ganges delta.

May consider a group  g=({0,1},+)g=({0,1},+)where  ++  will work as the xor operator like we work in boolean algebra. note here, that ‘00’ and ‘11’ are not the usual 0 and 1 that we work with everyday. the elements are  called  ‘00’ and ‘11’ and  may not mean  zero (nothing) and one (single). ‘00’ is the identity for the given binary operator +, meaning that any element operated with ‘00’ gets us that element itself.  for a set  ss  in  g′g′  having more elements than just  {0,1}{0,1}  the values for  a+b∈sa+b∈s, such that  a∈s,b∈sa∈s,b∈s, have to be first defined, only then can you determine the value of  1+11+1. the answer could possibly have been  22  if oanswer is25,000