Q. Which of the following is the longest tributary of the river Ganga?
a. Chambal
b. Yamuna
c. Gomti
d. Gandak
The longest tributary of the river Ganga is the Yamuna river (1,380 kilometers). It is originated from Yamunotri glacier. The Ganga river joins the Yamuna at a distance of 770 kilometers from Hardwar near Allahabad.