Questions on Lowest Common Denominator
Multiple-choice questions for 6th grade, focusing on Lowest Common Denominators (LCD) in the context of:
• ✅ LCD characteristics
• ✅ Fraction comparison using LCD
• ✅ Ordering fractions using LCD
Lowest Common Denominator – Real-World Problems (Grade 6)
1. Sarah ate 1/3 of a chocolate bar, and Tom ate 1/4. Who ate more?
A) Sarah
B) Tom
C) They ate the same
D) Not enough information
E) Depends on the chocolate
2. Emily and Jake are filling bottles. Emily fills 3/5 of a bottle, and Jake fills 4/7. Who filled more?
A) Emily
B) Jake
C) They filled the same
D) Not enough info
E) Emily by 1/2
3. Which is the least common denominator of 3/4 and 5/6?
A) 12
B) 18
C) 24
D) 6
E) 8
4. Which set of fractions has 12 as the lowest common denominator?
A) 1/3 and 1/4
B) 1/2 and 1/6
C) 1/6 and 1/8
D) 2/5 and 3/6
E) 2/3 and 1/5
5. What is the lowest common denominator of 2/9 and 5/6?
A) 18
B) 36
C) 54
D) 27
E) 12
6. A pie was cut into 1/8 pieces. A cake was cut into 1/6 slices. What is the smallest number of slices that can represent both desserts equally?
A) 16
B) 24
C) 12
D) 8
E) 48
7. Arrange the fractions from least to greatest: 3/8, 1/2, 5/6.
A) 3/8, 1/2, 5/6
B) 1/2, 3/8, 5/6
C) 5/6, 3/8, 1/2
D) 1/2, 5/6, 3/8
E) 3/8, 5/6, 1/2
8. Two friends ran a race. Lucas ran 5/8 of the track, and Mia ran 3/4. Who ran farther?
A) Lucas
B) Mia
C) Same distance
D) Not enough info
E) Depends on the track
9. Order the fractions from greatest to least: 2/3, 4/9, 5/6
A) 5/6, 2/3, 4/9
B) 4/9, 5/6, 2/3
C) 2/3, 4/9, 5/6
D) 2/3, 5/6, 4/9
E) 5/6, 4/9, 2/3
10. Emma drank 2/5 of her juice, while Noah drank 1/2. Who drank more?
A) Emma
B) Noah
C) Same amount
D) Not enough data
E) Equal if bottles differ
11. What is the LCD of 5/12 and 7/18?
A) 36
B) 54
C) 24
D) 12
E) 72
12. You want to compare 3/4 and 7/10. What is their LCD?
A) 20
B) 30
C) 40
D) 60
E) 10
13. Order these from least to greatest: 5/12, 1/2, 2/3
A) 5/12, 1/2, 2/3
B) 1/2, 5/12, 2/3
C) 2/3, 5/12, 1/2
D) 1/2, 2/3, 5/12
E) 2/3, 1/2, 5/12
14. Which pair has a lowest common denominator of 40?
A) 1/8 and 1/10
B) 3/5 and 2/8
C) 2/4 and 3/10
D) 3/6 and 1/4
E) 1/5 and 1/3
15. An artist used 3/10 of a red paint tube and 2/5 of a blue one. Which fraction is larger?
A) 3/10
B) 2/5
C) Same
D) Depends on tube size
E) Not comparable
16. Which is the correct order from least to greatest: 7/10, 3/4, 2/5?
A) 2/5, 7/10, 3/4
B) 3/4, 7/10, 2/5
C) 2/5, 3/4, 7/10
D) 3/4, 2/5, 7/10
E) 2/5, 3/4, 7/10
17. What is the LCD of 3/8, 5/12, and 7/18?
A) 72
B) 144
C) 36
D) 96
E) 108
18. Which is the smallest among these: 5/6, 3/4, 4/5?
A) 3/4
B) 5/6
C) 4/5
D) They are equal
E) None of the above
19. Which has the largest value?
A) 7/12
B) 5/8
C) 3/5
D) 2/3
E) 4/7
20. What is the LCD of 1/6, 3/10, and 2/15?
A) 30
B) 60
C) 90
D) 15
E) 120
- Questions on Greatest Common Factor (GCF) - Using Lists & Factor Trees
- Questions on Equivalent Fractions
- Questions on Common Multiples
Answer Key with Explanations
# |
Answer |
Explanation |
|---|---|---|
1 |
A |
LCD = 12 → 1/3 = 4/12, 1/4 = 3/12 → 1/3 > 1/4 |
2 |
B |
LCD = 35 → 3/5 = 21/35, 4/7 = 20/35 → Emily > |
3 |
C |
LCM of 4 and 6 = 12 |
4 |
A |
1/3 and 1/4 → LCD = 12 |
5 |
A |
LCM of 9 and 6 = 18 |
6 |
B |
LCM of 8 and 6 = 24 slices |
7 |
A |
LCD = 24, 3/8 = 9/24, 1/2 = 12/24, 5/6 = 20/24 |
8 |
B |
LCD = 8 → Lucas = 5/8, Mia = 6/8 |
9 |
A |
LCD = 18 → 2/3 = 12, 4/9 = 8, 5/6 = 15 |
10 |
B |
LCD = 10 → 2/5 = 4/10, 1/2 = 5/10 |
11 |
A |
LCM of 12 and 18 = 36 |
12 |
A |
LCM of 4 and 10 = 20 |
13 |
A |
LCD = 12 → 5/12, 6/12, 8/12 |
14 |
A |
LCM of 8 and 10 = 40 |
15 |
B |
LCD = 10 → 3/10 vs 4/10 |
16 |
A |
Convert to 20ths: 2/5 = 8/20, 7/10 = 14/20, 3/4 = 15/20 |
17 |
A |
LCM of 8, 12, 18 = 72 |
18 |
A |
Convert to 60ths: 3/4 = 45, 5/6 = 50, 4/5 = 48 |
19 |
D |
Convert to 120ths: 2/3 = 80, largest |
20 |
B |
LCM of 6, 10, 15 = 60 |
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