Math Chapter 5.1 & 5.2
26. George made enough money by selling candy bars at 15 cents each to buy several cans of pop at 48 cents each. If he had no money left over, what is the fewest number of candy bars he could have sold?
16
32. What is the smallest counting number divisible by 2, 4, 5, 6, and 12?
2^2 x 3 x 5 = 60
25. The primes 2 and 3 are consecutive whole numbers. Is there another such pair of consecutive primes? Justify your answer
There are no other pairs, since every even number besides 2 is composite
9. Use the test for divisibility by 11 to determine which of the following numbers are divisible by 11. a. 2838 b. 71,992 c. 172,425
a & c
21. In the following problems, you are given three pieces of information. Use them to answer the question. a. GCF( a,b ) = 2 × 3 LCM(a,b) = 2^2 x 3^3 x 5 b = 2^2 x 3 x 5. What is a?
a = 2 x 3^3
9. Use the set intersection method to find the following LCMs. a. LCM(24, 30) b. LCM(42, 28) c. LCM(12, 14)
a. 120 b. 84 c. 84
7. Use any method to find the following GCFs. a. GCF(51, 85) b. GCF(45, 75) c. GCF(42, 385) d. GCF(117, 195)
a. 17 b. 15 c. 7 d. 39
4. Use the prime factorization method to find the GCFs. a. GCF(8, 18) b. GCF(36, 42) c. GCF(24, 66)
a. 2 b. 6 c. 6
13. Which of the following numbers are composite? Why? a. 12 b. 123 c. 1234 d. 12,345
a. 2 12 b. 3 123 c. 2 1234 d. 5 12,345
13. Use any method to find the following LCMs. a. LCM(2, 3, 5) b. LCM(8, 12, 18)
a. 2 x 3 x 5 b. 2^3 x 3^2
10. Use the (i) prime factorization method and the (ii) buildup method to find the following LCMs. a. LCM(6, 8) b. LCM(4, 10) c. LCM(7, 9) d. LCM(8, 10)
a. 24 b. 20 c. 63 d. 40
11. Find the following LCMs using any method. a. LCM(60, 72) b. LCM(35, 110) c. LCM(45, 27)
a. 360 b. 770 c. 135
8. Which of the following are multiples of 3? of 4? of 9? a. 123,452 b. 1,114,500
a. 4 only b. 3, 4
1. How many factors do each of the following numbers have? a. 2^2 x 3 b. 3^3 x 5 c. 5^2 x 7^3 x 11^4
a. 6 b. 12 c. 60
5. Find the following. a. GCF(138, 102) b. GCF(484, 363) c. GCF(297, 204) d. GCF(222, 2222)
a. 6 b. 121 c. 3 d. 2
3. Use the set intersection method to find the GCFs. a. GCF(12, 18) b. GCF(42, 28) c. GCF(60, 84)
a. 6 b. 14 c. 12
12. Use any method to find the following GCFs. a. GCF(12, 60, 90) b. GCF(55, 75, 245) c. GCF(1105, 1729, 3289) d. GCF(1421, 1827, 2523)
a. 6 b. 5 c. 13 d. 1
8. Two counting numbers are relatively prime if the greatest common factor of the two numbers is 1. Which of the following pairs of numbers are relatively prime? a. 4 and 9 b. 24 and 123 c. 12 and 45
a. only
