Least Common Multiple (LCM), Fifth Grade Test, Free Math Test

Question 1 (1 point)

The multiples of 12 are
12, 24, 36, 48, 60, 72,...
The multiples of 24 are
24, 48, 72, 96,...
In blue are the multiples that are common to 12 and 24.
What is the Least Common Multiple of 12 and 24?
LCM(12, 24) = ?

Question 2 (1 point)

The multiples of 5 are:
5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125,...
The multiples of 6 are:
6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72, 78, 84, 90, 96, 102, 108, 114, 120,...
The multiples of 8 are:
8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 104, 112, 120,...
What is the Least Common Multiple of 5, 6 and 8?
LCM(5, 6, 8) = ?

Question 3 (1 point)

The image shows the decomposition of 5, 6, 4 in their prime factors.
$LCM(5,6,4)= $

The image shows the decomposition of 5, 6, 4 in their prime factors.<br />
$LCM(5,6,4)= $

$LCM(5,6,4)=2\cdot 2\cdot 3\cdot 3\cdot 5 \cdot 5=900$

$LCM(5,6,4)=2 \cdot 3\cdot 5=30$

$LCM(5,6,4)=2+3+5=10$

$LCM(5,6,4)=2\cdot 2\cdot 3 \cdot 5=60$

Question 4 (1 point)

The number [tex]36[/tex] is divisible by [tex]9[/tex]. What is the least common multiple of [tex]9[/tex] and [tex]36[/tex]?

Question 5 (2 points)

Two buses leave the station together at 8:00. The first bus leaves every [tex]12[/tex] minutes and the second every [tex]18[/tex] minutes. After how many minutes will they next leave the station together?

Question 6 (1 point)

[tex]12 = 2 \cdot 2 \cdot 3[/tex] and [tex]18 = 2 \cdot 3 \cdot 3[/tex]. What is the least common multiple of [tex]12[/tex] and [tex]18[/tex]?

[tex]2 \cdot 3 = 6[/tex]

[tex]2 \cdot 2 \cdot 3 \cdot 3 = 36[/tex]

[tex]2 \cdot 2 \cdot 2 \cdot 3 \cdot 3 \cdot 3 = 216[/tex]

[tex]2 \cdot 2 \cdot 3 = 12[/tex]

Question 7 (1 point)

The least common multiple of [tex]6[/tex] and [tex]\boxed{\phantom{0}}[/tex] is [tex]18[/tex]. Which number could go in the box?

Two lights blink at the same moment. One blinks every [tex]4[/tex] seconds, the other every [tex]6[/tex] seconds. After how many seconds will they blink together again?

[tex]12[/tex] red and [tex]18[/tex] blue beads are packed into identical bags with none left over. What is the largest possible number of bags?

A class has [tex]12[/tex] girls and [tex]18[/tex] boys. How many more boys than girls are there?

A class has [tex]12[/tex] girls and [tex]18[/tex] boys. How many children are there altogether?

Question 9 (2 points)

The marbles in a box can be shared equally among [tex]6[/tex] children or among [tex]8[/tex] children with none left over. What is the smallest number of marbles that could be in the box?

The least common multiple of two numbers is always their product.

The least common multiple of two numbers is always smaller than both of them.

The least common multiple of two numbers can be smaller than the larger of the two.

The least common multiple of two numbers is never smaller than the larger of the two.

Question 11 (1 point)

Which of the fractions [tex]\frac{3}{4},\ \frac{5}{6},\ \frac{7}{12}[/tex] and [tex]\frac{2}{3}[/tex] is the greatest?

Question 12 (2 points)

What is the smallest number greater than [tex]100[/tex] that is a multiple of both [tex]6[/tex] and [tex]8[/tex]?

Question 13 (1 point)

What is the least common denominator of [tex]\frac{5}{6}[/tex] and [tex]\frac{3}{8}[/tex]?

Question 14 (2 points)

When the eggs on a farm are packed in boxes of [tex]4[/tex], exactly [tex]1[/tex] egg is left over. The same happens with boxes of [tex]5[/tex] and with boxes of [tex]6[/tex]. What is the smallest possible number of eggs, if there is more than one egg?

Question 15 (1 point)

[tex]p[/tex] and [tex]q[/tex] are two different prime numbers. What is their least common multiple?

Least Common Multiple (LCM), Fifth Grade Test

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