In a row of boys Pratik and Krishna occupies 10th from left and 17th from the right position respectively. There are ten persons sitting between Pratik and Krishna. How many person’s are there is a row

37

Total   = 10 + 10 + 17

= 37

alternate method,

From the above figure we get to know that ,.

Krishna position is 21^st from the left

therefore

total number of person = left position + right position -1

                           =21+17-1

                           =37