If two students, Sarah and Tom, swap their positions in a ranking of 40 students, and Sarah is currently 10th from the top, what will be her new rank from the bottom if Tom is 31st from the top?
If two students, Sarah and Tom, interchange their seats, and Sarah is ranked 10th from the top and Tom is ranked 20th from the bottom, what is the total number of students?
In a group of 40 people, if Tom is 10th from the top and after swapping places with another person, he becomes 15th from the top. What is the rank of the person who swapped with him from the bottom?