Which least number must be subtracted from each of the term 35, 50, 25, 35 to make them proportional?

5

To make these numbers in proportion, the condition should be:

(35 - a) : (50 - a) :: (25 - a) : (35 - a)

Check from the option, which is the best way to find the number.

So, Option (c):- 5 will justify the equation.

(35 - 5) : (50 - 5) :: (25 - 5) : (35 - 5)

    30    :      45    ::     20    :     30

     2     :       3    ::       2    :      3

Therefore, 5 is correct answer.