Question

explain the answer of that question

Answer 1

the less than ogive curve gives cumulative frequency (probability) for x ≤ a

The more than ogive curve gives cumulative frequency (probability) for x ≥a

They intersect exactly at the median as the cumulative frequency will be 50% of the total at median. So the coordinate of x axis will be the median .
And when we draw perpendicular to the intersection also they meet at co-ordinate of x axis.

So the median is 20.5

I hope it helps u