(815 / ?) / 100 * 28 * 3 – (815 * 14 * 6)/100 = 1680

A. 2000
B. 3000
C. 4000
D. 6000

Explanation:

Let 815 + ? be k

=> 84k/100 – (815 * 84)/100 = 1680
=>84(k/100 – 815/100) = 1680
=> (k – 815)/100 = 20 => k = 2815
k = 815 + ? = 2815 => ? = 2000