What should be subtracted from 15, 21, 27, and 39 so that the resulting numbers are proportional?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 3.
Let the number to be subtracted = x
So, (15 - x)/(21 - x) = (27 - x)/(39 - x)
⇒ 585 - 54x + x2 = 567 - 48x + x2
⇒ 6x = 18
⇒ x = 3