In a row of 45 students facing North, Krishna is 7th of the left of Sonam. If Sonam is 20th from the left end of the row, how far is Krishna from the right end of the row?

28 24 26 27

27

Total = 45 Sonam is 20th from the left  therefore, Krishna is 13th from left (20 - 7 = 13)   T = Left Rank + Right Rank - 1 40 = 13 + R - 1 R = 27