Interchange with Unknown - Intermediate Level: tricky scenarios handling Interchange with Unknown INTERMEDIATE

This expert challenge 📈 worksheet focuses on Interchange with Unknown - a key topic in Number Ranking. You'll solve 20 intermediate-level problems (Worksheet 5 of 10). The primary focus is on tricky scenarios handling. Master how to solve interchange with unknown, interchange with unknown tricks, and interchange with unknown shortcut methods through systematic practice.

📝 Worksheet 5 of 10 • 20 questions • ⏱️ Estimated time: 20 minutes • 🎯 Intermediate level

What you'll learn in this worksheet:
Your progress through Interchange with Unknown
Worksheet 5 of 10 (44% complete)

Question 1

In a row of 41 people, A is 10th from the left. After interchanging positions with B, A becomes 13th from the left. B originally was 16th from the right. What is A's new rank from the right?
After interchange, A's new left rank is 13. So A's new right rank = total - new_left + 1 = 41 - 13 + 1 = 29.

Question 2

In a row of 48 people, after interchanging positions with B, A becomes 12th from the left and 37th from the right. If B was originally 14th from the right, what was A's original rank from the left?
Since B took A's original position, and B's original right rank was 14, we can find A's original left rank = total - r2_right + 1 = 48 - 14 + 1 = 8.

Question 3

In a row of 53 people, A is 9th from the left. After interchanging positions with B, A becomes 16th from the left. B originally was 16th from the right. What is A's new rank from the right?
After interchange, A's new left rank is 16. So A's new right rank = total - new_left + 1 = 53 - 16 + 1 = 38.

Question 4

In a row of 50 people, A is 9th from the left. After interchanging positions with B, A becomes 12th from the left. B originally was 12th from the right. What is A's new rank from the right?
After interchange, A's new left rank is 12. So A's new right rank = total - new_left + 1 = 50 - 12 + 1 = 39.

Question 5

In a row of 45 people, A is 12th from the left. After interchanging positions with B, A becomes 17th from the left. B originally was 10th from the right. What is A's new rank from the right?
After interchange, A's new left rank is 17. So A's new right rank = total - new_left + 1 = 45 - 17 + 1 = 29.

Question 6

In a row of 40 people, A is 12th from the left. After interchanging positions with B, A becomes 18th from the left. B originally was 14th from the right. What is A's new rank from the right?
After interchange, A's new left rank is 18. So A's new right rank = total - new_left + 1 = 40 - 18 + 1 = 23.

Question 7

In a row of 39 people, after interchanging positions with B, A becomes 19th from the left and 21th from the right. If B was originally 13th from the right, what was A's original rank from the left?
Since B took A's original position, and B's original right rank was 13, we can find A's original left rank = total - r2_right + 1 = 39 - 13 + 1 = 15.

Question 8

In a row of 49 people, after interchanging positions with B, A becomes 20th from the left and 30th from the right. If B was originally 13th from the right, what was A's original rank from the left?
Since B took A's original position, and B's original right rank was 13, we can find A's original left rank = total - r2_right + 1 = 49 - 13 + 1 = 15.

Question 9

In a row of 40 people, A is 13th from the left. After interchanging positions with B, A becomes 21th from the left. B originally was 12th from the right. What is A's new rank from the right?
After interchange, A's new left rank is 21. So A's new right rank = total - new_left + 1 = 40 - 21 + 1 = 20.

Question 10

In a row of 43 people, after interchanging positions with B, A becomes 17th from the left and 27th from the right. If B was originally 16th from the right, what was A's original rank from the left?
Since B took A's original position, and B's original right rank was 16, we can find A's original left rank = total - r2_right + 1 = 43 - 16 + 1 = 10.

Question 11

In a row of 43 people, after interchanging positions with B, A becomes 19th from the left and 25th from the right. If B was originally 12th from the right, what was A's original rank from the left?
Since B took A's original position, and B's original right rank was 12, we can find A's original left rank = total - r2_right + 1 = 43 - 12 + 1 = 15.

Question 12

In a row of 49 people, after interchanging positions with B, A becomes 20th from the left and 30th from the right. If B was originally 13th from the right, what was A's original rank from the left?
Since B took A's original position, and B's original right rank was 13, we can find A's original left rank = total - r2_right + 1 = 49 - 13 + 1 = 15.

Question 13

In a row of 37 people, A is 8th from the left. After interchanging positions with B, A becomes 13th from the left. B originally was 12th from the right. What is A's new rank from the right?
After interchange, A's new left rank is 13. So A's new right rank = total - new_left + 1 = 37 - 13 + 1 = 25.

Question 14

In a row of 43 people, after interchanging positions with B, A becomes 16th from the left and 28th from the right. If B was originally 15th from the right, what was A's original rank from the left?
Since B took A's original position, and B's original right rank was 15, we can find A's original left rank = total - r2_right + 1 = 43 - 15 + 1 = 10.

Question 15

In a row of 39 people, after interchanging positions with B, A becomes 18th from the left and 22th from the right. If B was originally 17th from the right, what was A's original rank from the left?
Since B took A's original position, and B's original right rank was 17, we can find A's original left rank = total - r2_right + 1 = 39 - 17 + 1 = 15.

Question 16

In a row of 38 people, after interchanging positions with B, A becomes 13th from the left and 26th from the right. If B was originally 17th from the right, what was A's original rank from the left?
Since B took A's original position, and B's original right rank was 17, we can find A's original left rank = total - r2_right + 1 = 38 - 17 + 1 = 10.

Question 17

In a row of 46 people, A is 8th from the left. After interchanging positions with B, A becomes 15th from the left. B originally was 10th from the right. What is A's new rank from the right?
After interchange, A's new left rank is 15. So A's new right rank = total - new_left + 1 = 46 - 15 + 1 = 32.

Question 18

In a row of 43 people, after interchanging positions with B, A becomes 19th from the left and 25th from the right. If B was originally 13th from the right, what was A's original rank from the left?
Since B took A's original position, and B's original right rank was 13, we can find A's original left rank = total - r2_right + 1 = 43 - 13 + 1 = 13.

Question 19

In a row of 41 people, after interchanging positions with B, A becomes 20th from the left and 22th from the right. If B was originally 15th from the right, what was A's original rank from the left?
Since B took A's original position, and B's original right rank was 15, we can find A's original left rank = total - r2_right + 1 = 41 - 15 + 1 = 13.

Question 20

In a row of 46 people, after interchanging positions with B, A becomes 15th from the left and 32th from the right. If B was originally 13th from the right, what was A's original rank from the left?
Since B took A's original position, and B's original right rank was 13, we can find A's original left rank = total - r2_right + 1 = 46 - 13 + 1 = 11.
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