Common Information
There are two rows of numbers in each question. The upper row is complete and in the lower one number is missing. Find a suitable number to fill the blank space so that the symmetry with the upper row is maintained.
Q. 
Common Information Question: 1/2 Table below can be scrolled horizontally

✖ A.  211 
✖ B.  125 
✖ C.  117 
✔ D.  75 
Solution:
Option(D) is correct
From the first row, $\dfrac{17 \times 12}{2} = 102$
From the second row, $\dfrac{15 \times 10}{2} = 75$
Hence, option D is the correct choice