The HCF of 910 , 1225 , 1835 and 2140 is = ?

Answer: Option C

$$\begin{array}{rl}& \text{Required HCF }\\ & \text{ = }\frac{\text{HCF of 9,12,18,21}}{\text{LCM of 10,25,35,40}}\\ & =\frac{3}{1400}\end{array}$$