Least Common Multiple by the Factor Method

Try these questions

5 questions from this lesson’s quiz. Start the lesson to answer them and see the right answers.

1. 1. Which rule is used to find the Least Common Multiple (LCM) of two numbers by the factor method?

   • A. Multiply the lowest powers of the common prime factors only
   • B. Multiply the highest powers of every prime factor that appears
   • C. Add the prime factors of the two numbers
   • D. Multiply the lowest powers of every prime factor that appears

2. 2. Find the LCM of 20 and 30 using prime factorisation.

   Type your answer in the lesson.

3. 3. Two numbers have prime factorisations 2^2 \times 3^3 and 2^3 \times 3^2. What is their LCM?

   Type your answer in the lesson.

4. 4. At a matatu stage in Nairobi, Matatu A leaves every 15 minutes and Matatu B leaves every 20 minutes. Both leave together at 7:00 a.m. After how many minutes will they next leave together?

   Type your answer (in minutes) in the lesson.

5. 5. What is the LCM of 18, 24 and 30?

   • A. 120
   • B. 180
   • C. 360
   • D. 720

More in Factors

• ▸Subtraction of Whole Numbers
• ▸Divisibility Tests for 3, 6, 9 and 11
• ▸Composite Numbers as a Product of Prime Factors
• ▸Greatest Common Divisor by Factor Method
• ▸Applying GCD and LCM in Real Life Situations
• ▸Factor Games, IT Devices and Revision
• ▸Comparing and Ordering Fractions
• ▸Adding Fractions

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