Reverse Thinking( Week 2 Evaluation) 1. When 13 is added to a certain number, the answer is 58. What is the number? 2. 21 plus a certain number is 91. What is the number? 3. Emily is 17 years old, which is equal to half of Kevin's age of next year. What is the age of Kevin now? 4. There were 40 books in a bookshelf originally. After half of the storybooks were borrowed by students, 24 books were left in the shelf. How many storybooks were there originally? 5. Number A is reduced by 7 and the result is then added by 9. The final result is 12. What is the number A? 6. A Number X is added to 10 and the result is then reduced by 2. The final result is 17. What is the number X? 7. There are equal number of male and female in a club. All the male like football as well as half of the female. If there are 45 family members that like the football, how many female are there in the club? 8. Laura entered an elevator at a certain floor. Then the elevator moved up 6 floors, down 8 floors, and up 5 floors. Finally, Laura was at floor 8. At which floor did Laura initially enter the elevator? 9. After a rope is folded three times, the length is 9 meters. How long was the rope originally? 10. A father is 40 years old now, and is 4 times as old as his son was 2 years ago. How old is the son this year? |