Math Olympiad 3( Week 51 Quiz 10) 2. Using all the numbers of 4, 7, 12, 17, 21 and +, − operations, can an even number be made? 3. What is the least common multiple of 8 and 18? 4. Make a 1 using the giving numbers with operators (), +, -, *, /. When making the number, it is required to use each of the five numbers from 3, 4, 5, 6, and 7 exactly once. But there is no limit in how many of the operators (), +, -, *, / to be used. = 1 5. Make a 3 using the giving numbers with operators (), +, -, *, /. When making the number, it is required to use each of the five numbers from 3, 4, 5, 6, and 7 exactly once. But there is no limit in how many of the operators (), +, -, *, / to be used. = 3 6. Make a 5 using the giving numbers with operators (), +, -, *, /. When making the number, it is required to use each of the five numbers from 5, 6, 7, 8, and 9 exactly once. But there is no limit in how many of the operators (), +, -, *, / to be used. = 5 7. Make a 7 using the giving numbers with operators (), +, -, *, /. When making the number, it is required to use each of the five numbers from 1, 2, 3, 4, and 5 exactly once. But there is no limit in how many of the operators (), +, -, *, / to be used. = 7 8. Make a 9 using the giving numbers with operators (), +, -, *, /. When making the number, it is required to use each of the five numbers from 1, 2, 3, 4, and 5 exactly once. But there is no limit in how many of the operators (), +, -, *, / to be used. = 9 11. Write down the first 2 common multiples of 2, 4 and 6. 12. A positive integer can be divisible by 4, 5, and 6. What is the least possible value for the number? 13. How many factors does 20 have? 14. There are a certain number of ducks and rabbits, which have 20 heads and 58 legs all together. How many ducks and rabbits are there respectively? (Only write down the numbers separated by a comma). 15. There are a certain number of pencils to be distributed among a certain number of students. There is no pencil left if each student gets 5 pencils. There is also no pencil left if each student gets 6 pencils. What is the smallest possible number of pencils? |