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What Is the LCM of 26 and 91

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How to Find the LCM of 26 and 91 Using Prime Factorization

The concept of LCM of 26 and 91 is essential in mathematics and helps in solving real-world and exam-level problems efficiently. Finding the least common multiple of two numbers is especially useful in dealing with fractions, scheduling, and class 10 board exam questions.


Understanding LCM of 26 and 91

The LCM of 26 and 91 (Least Common Multiple) is the smallest number that is exactly divisible by both 26 and 91. This concept is widely used in fraction addition/subtraction, solving time-based problems in maths, and exam revision sessions. Knowing how to find the LCM using prime factorization and the division method is an important skill for students preparing for school and competitive exams.


Formula Used in LCM of 26 and 91

The standard formula is: \( \text{LCM}(a, b) = \frac{a \times b}{\text{HCF}(a, b)} \)

For manual calculation, the LCM can be found by taking all the prime factors from both numbers, using the highest powers present.


Finding the LCM of 26 and 91 - Stepwise Methods

Method 1: Prime Factorization

1. Find prime factors of both numbers.

26 = 2 × 13
91 = 7 × 13

2. List all unique prime factors (use each common factor only once, with its highest power).

Unique factors are: 2, 7, and 13

3. Multiply these prime factors:

LCM = 2 × 7 × 13 = 182

Therefore, LCM(26, 91) = 182.

Method 2: Division (Ladder) Method

1. Write numbers 26 and 91 side by side.

2. Divide both numbers by the smallest prime number that divides at least one of them. For each step, bring the quotient below.

Step 1: 2 divides 26 (26/2=13, 91 unchanged)

Step 2: 7 divides 91 (13 unchanged, 91/7=13)

Step 3: 13 divides both (13/13=1, 13/13=1)

3. Multiply all the divisors used: 2 × 7 × 13 = 182

So, LCM(26, 91) = 182.


LCM and HCF Relationship for 26 and 91

The relationship between LCM and HCF (Highest Common Factor) is vital in exams. The formula is:

LCM × HCF = Product of the numbers

For 26 and 91: HCF = 13 (since 13 is the highest number that divides both).
Check: 182 × 13 = 2366
Also, 26 × 91 = 2366. The relation holds true!


Here’s a helpful table to understand the LCM of 26 and 91 more clearly:


LCM and HCF Table for 26 and 91

Number Prime Factors HCF LCM
26 2 × 13 13 182
91 7 × 13

This table shows the factor breakdown and makes it easy to check the answer during exams.


Worked Example – Solving LCM of 26 and 91

1. Write both numbers: 26 and 91.

2. Find prime factors:

26 = 2 × 13
91 = 7 × 13

3. LCM must include each prime factor at the highest power:
Take 2 (once), 7 (once), and 13 (once)

4. Multiply all the selected prime factors:
2 × 7 × 13 = 182


Practice Problems

  • Find the LCM of 26 and another number, like 39 or 65.
  • If HCF(26, x) = 13 and LCM(26, x) = 182, what is x?
  • List the common multiples of 26 and 91 up to 500.
  • What is the LCM of 26, 91, and 13?

Common Mistakes to Avoid

  • Confusing LCM with HCF – remember LCM is the smallest number divisible by both, HCF is the largest that divides both.
  • Omitting common primes or repeating shared factors in multiplication (use each common factor only once with the highest power).
  • Not checking the answer using the product-HCF-LCM relationship.

Real-World Applications

The concept of LCM of 26 and 91 appears in areas such as adding/subtracting unlike fractions, synchronizing events (e.g., two lights blinking every 26 and 91 seconds), and timetable management. Vedantu helps students see how these maths skills apply both in exams and in real life.


We explored the idea of LCM of 26 and 91, how to apply it with step-by-step solutions, check the result with the HCF-LCM relationship, and reviewed real-life uses. Practice more with Vedantu to build strong foundations in such topics and gain confidence for your board exams.


Related Learning Resources


FAQs on What Is the LCM of 26 and 91

1. What is the LCM of 26 and 91?

The LCM of 26 and 91 is 182.

  • Prime factorization of 26 = 2 × 13
  • Prime factorization of 91 = 7 × 13
  • Take highest powers of each prime: 2, 7, and 13
  • Multiply: 2 × 7 × 13 = 182
The least common multiple (LCM) is the smallest number that both 26 and 91 divide exactly.

2. How do you find the LCM of 26 and 91 using prime factorization?

You find the LCM of 26 and 91 by multiplying the highest powers of all prime factors involved.

  • 26 = 2 × 13
  • 91 = 7 × 13
  • LCM = 2 × 7 × 13
  • LCM = 182
This method ensures you include each prime factor only once at its greatest exponent.

3. Can you find the LCM of 26 and 91 using the GCD method?

Yes, the LCM of 26 and 91 using the GCD method is 182.

  • Formula: LCM(a, b) = (a × b) / GCD(a, b)
  • GCD of 26 and 91 = 13
  • LCM = (26 × 91) ÷ 13
  • LCM = 2366 ÷ 13 = 182
This formula connects the greatest common divisor (GCD) and least common multiple (LCM).

4. What is the GCD of 26 and 91?

The GCD of 26 and 91 is 13.

  • Factors of 26: 1, 2, 13, 26
  • Factors of 91: 1, 7, 13, 91
  • Common factors: 1 and 13
  • Greatest common factor = 13
The GCD (greatest common divisor) is the largest number that divides both numbers exactly.

5. Why is 182 the least common multiple of 26 and 91?

The number 182 is the least common multiple because it is the smallest number divisible by both 26 and 91.

  • 182 ÷ 26 = 7
  • 182 ÷ 91 = 2
No smaller positive number is divisible by both, so 182 is the smallest common multiple.

6. What are the common multiples of 26 and 91?

The common multiples of 26 and 91 are multiples of their LCM, which is 182.

  • First common multiple: 182
  • Next: 364
  • Next: 546
  • Next: 728
Common multiples are found by multiplying the LCM by 1, 2, 3, and so on.

7. What is the formula for finding the LCM of two numbers?

The formula to find the LCM of two numbers is LCM(a, b) = (a × b) / GCD(a, b).

  • First, find the GCD of the numbers
  • Multiply the two numbers
  • Divide the product by the GCD
Using this formula for 26 and 91 gives LCM = 182.

8. What is the relationship between the LCM and GCD of 26 and 91?

The relationship is given by LCM × GCD = Product of the two numbers.

  • LCM of 26 and 91 = 182
  • GCD of 26 and 91 = 13
  • 182 × 13 = 2366
  • 26 × 91 = 2366
This confirms the identity holds true for these numbers.

9. Are 26 and 91 relatively prime numbers?

No, 26 and 91 are not relatively prime because their GCD is 13.

  • Relatively prime numbers have GCD = 1
  • Since GCD(26, 91) = 13, they share a common factor
Therefore, they are not coprime numbers.

10. What are the prime factors of 26 and 91?

The prime factors of 26 are 2 and 13, and the prime factors of 91 are 7 and 13.

  • 26 = 2 × 13
  • 91 = 7 × 13
Prime factorization helps in finding both the LCM and GCD efficiently.