"First, second, third"

Translation: पहला, दूसरा, तीसरा

[GoWiP]

So, actually, why is this not written दूस्रा and तीस्रा?
Oftentimes 2 consonants next to each other, as here, get connected (बिल्ली, दोस्त, ...)

[ph.KP37fO]

There is a difference between ra and tra

[Laya.S.Gow]

Hi