How do you find the HCF and LCM in word problems?

How do you find the HCF and LCM in word problems?

Word problems on H.C.F. and L.C.M.

1. Therefore, least common multiple (L.C.M.) of 28, 36 and 45 = 2 × 2 × 3 × 3 × 5 × 7 = 1260.
2. Therefore, the required number = 1260 – 19 = 1241.
3. Highest common factor (H.C.F.) of 90 and 162 = 18.
4. Relationship between H.C.F. and L.C.M.
5. Worksheet on H.C.F. and L.C.M.

What are key words for LCM?

Terms in this set (19)

• Greatest. GCF.
• Largest. GCF.
• Maximum. GCF.
• Dividing Something (combinations) GCF.
• Cutting Something into Pieces. GCF.
• Smallest. LCM.
• Minimum. LCM.
• First. LCM.

How do you find the HCF of a word problem?

Solution: The greatest number that divides both 90 and 126 exactly is their HCF. We can find HCF by long division method. HCF of 90 and 126 is 18.

How do you solve LCM questions?

Find the least common multiple (LCM) of two numbers by listing multiples

1. List the first several multiples of each number.
2. Look for multiples common to both lists.
3. Look for the smallest number that is common to both lists.
4. This number is the LCM.

What is the easiest way to find the LCM trick?

How to Find the LCM – FAST!!!

1. Step 1) Find the GCF for the two numbers. For 18 and 30, GCF is 6.
2. Step 2) Divide that GCF into either number; it doesn’t matter which one you choose, so choose the one that’s easier to divide. Choose 18.
3. Step 3) Take that answer and multiply it by the other number.
4. Step 4) Celebrate …

How do you solve for LCM?

One way to find the least common multiple of two numbers is to first list the prime factors of each number. Then multiply each factor the greatest number of times it occurs in either number. If the same factor occurs more than once in both numbers, you multiply the factor the greatest number of times it occurs.

How do you find the LCM of a word problem?

Solution

1. A bell rings every 18 seconds, another every 60 seconds. Prime factorizations of 18 and 60 are.
2. LCM is the product of maximum occurrences of each prime factor in the given numbers.
3. So L C M 12,18 = 2 × 2 × 3 × 3 × 5 = 180 seconds = 180/60 = 3 minutes. So the bells will ring at same time again at 5.03pm.

What is the formula of HCF and LCM?

HCF and LCM of two numbers are related to each other as well as with the given numbers. For any two numbers a and b, HCF (a, b) × LCM (a, b) = a × b.

How is LCM calculated?

What is the easiest way to find the LCM?

Praveen, The easiest way to find the LCM for two or more numbers is this. First, prime factorize the three numbers. Secondly, line up the prime factors. Thirdly, for each prime number, choose the largest factor. Fourthly, multiply the LCM factors together. The product will be the LCM of the various numbers.

How do you calculate least common multiple?

One way to find the least common multiple of two numbers is to first list the prime factors of each number. Then multiply each factor the greatest number of times it occurs in either number. If the same factor occurs more than once in both numbers, you multiply the factor the greatest number of times it occurs.

How to calculate HCF?

Write down each number as the product of its prime factors.

Now,list down the common factors from the given numbers.

The largest number,which is found in the common factors is the HCF of the given numbers.

How do you calculate greatest common factor?

To find the greatest common factor (GCF) between numbers, take each number and write it’s prime factorization. Then, identify the factors common to each number and multiply those common factors together.