Online Test — Prime Factorization, LCM, GCF
10 Questions • 30 min • Chapter MCQ
30:00
Question 1 of 10
easy
What is the prime factorization of 28?
2×14
4×7
2²×7
2×2×2×7
Explanation: 28=4×7=2²×7
Question 2 of 10
easy
Find GCF(12, 20)
2
4
6
10
Explanation: Factors:12:1,2,3,4,6,12; 20:1,2,4,5,10,20 → GCF=4
Question 3 of 10
easy
Find LCM(4, 10)
20
40
10
30
Explanation: Multiples of4:4,8,12,16,20; of10:10,20 → LCM=20
Question 4 of 10
easy
Which number is prime?
1
9
15
17
Explanation: Prime has exactly 2 factors: 17 only
Question 5 of 10
medium
GCF(24, 36) = ?
6
8
12
18
Explanation: 24=2³×3,36=2²×3² → common:2²×3=12
Question 6 of 10
medium
LCM(6, 15) = ?
30
45
60
90
Explanation: 6=2×3,15=3×5 → LCM=2×3×5=30
Question 7 of 10
medium
Prime factorization of 72 is?
2³×3²
2²×3³
8×9
2⁴×3
Explanation: 72=8×9=2³×3²
Question 8 of 10
medium
Two bells ring every 8 and 12 seconds. When next together?
20 sec
24 sec
32 sec
36 sec
Explanation: LCM(8,12)=24 seconds
Question 9 of 10
medium
GCF(14, 21) = ?
1
3
7
14
Explanation: 14=2×7,21=3×7 → GCF=7
Question 10 of 10
medium
LCM(9, 15) = ?
30
45
60
75
Explanation: 9=3²,15=3×5 → LCM=3²×5=45