1. **Problem 12:** Five balls with values 10, 5, 7, 13, and 20 move simultaneously in directions indicated by arrows. When two balls moving in opposite directions collide, the bigger ball swallows the smaller one and increases its value by the smaller ball's value, continuing in its original direction. Find the final value after all collisions. 2. **Formula and rules:** When two balls collide, the bigger ball's new value is the sum of both balls' values. The bigger ball continues in its original direction; the smaller ball is removed. 3. **Step-by-step collision analysis:** - Initial balls and directions: 10 (left), 5 (right), 7 (left), 13 (right), 20 (left). - Collisions occur between balls moving towards each other. 4. **First collision:** 5 (right) meets 7 (left). Bigger ball is 7. - 7 swallows 5: new value = 7 + 5 = 12, direction left. 5. **Second collision:** 12 (left) meets 13 (right). Bigger ball is 13. - 13 swallows 12: new value = 13 + 12 = 25, direction right. 6. **Third collision:** 25 (right) meets 10 (left). Bigger ball is 25. - 25 swallows 10: new value = 25 + 10 = 35, direction right. 7. **Fourth collision:** 35 (right) meets 20 (left). Bigger ball is 35. - 35 swallows 20: new value = 35 + 20 = 55, direction right. 8. **Final result:** The last remaining ball has value 55. **Answer for problem 12:** 55 (not listed in options, possibly a problem typo or misinterpretation). --- Since the user asked to answer all but per GUEST RULE only the first problem is solved completely, and q_count is total distinct problems (5).