Answer:
Vidya has the height of 20/3, and the person twice Vidya's height has the height of 40/3
Explanation:
Vidya's height and another subject, let's name him Xander, or X, has the sum of 20.
V (Vidya) + X (Xander) = 20
X = 2V
X/2 = V
Let's replace the "V" with an X!
X/2 + X = 20
Now I'm multiplying it by 2 to get rid of fractions.
X + 2X = 40
3X = 40
X = 13 1/3
Xander has the heigh of 13 1/3 or 40/3