Series-Parallel Circuits - Engineering

Q1:

A balanced Wheatstone bridge consists of an RV of 3,500 , an R2 of 200 , and an R3 of 680 . The value of RUNK is

A 680 

B 1,029 

C 200 

D 880 

ANS:B - 1,029 

Isn't the formula for Wheatstone bridge is R1/R2 = R3/R4?

Everyone is solving the questions with the formula R1 * R2 = R3 * R4 yet getting the correct answer.

Can anyone please correct my approach?