C and D are seated in a row of 15 people. C is 3rd from the left and D is 4th from the right. If they swap seats, what will be C's new rank from the left?
Answer: C. 5th
After swapping seats, C will take D's position, which is 4th from the right. In a row of 15, that makes C's new position 15 - 4 + 1 = 12th from the left.