Question : How many children are there in the row of children facing North ?

Statements :
I. Vishakha who is fifth from the left end is eighth to the left of Ashish who is twelfth from the right end.
II. Rohit is fifth to the left of Nisha who is seventh from the right end and eighteenth from the left end.

Explanation:-

Since 8th to the left of 12th from the right is 20th from the right, so from I, we know that Vishakha is 5th from left and 20th from right i.e. there are 4 children to the left and 19 to the right of Vishakha. So, there are (4 + 1 + 19) i.e. 24 children in the row.

From II, Nisha is 7th from right and 18th from left end of the row.
So, there are (6 + 1 + 17) = 24 children in the row.