Math Problem Statement

The highest common factor of two numbers is 175 the lowest common multiple of these two numbers is 12600 both numbers are greater than they highest common factor find the two numbers

Solution

We are given the following information:

  • The Highest Common Factor (HCF) of two numbers is 175.
  • The Lowest Common Multiple (LCM) of these two numbers is 12,600.
  • Both numbers are greater than the HCF.

We can use the relationship between the HCF, LCM, and the product of two numbers to solve this problem. The formula that relates these quantities is:

HCF×LCM=Product of the two numbers\text{HCF} \times \text{LCM} = \text{Product of the two numbers}

Let's denote the two numbers as aa and bb. From the formula, we have:

175×12,600=a×b175 \times 12,600 = a \times b

Calculating the product:

175×12,600=2,205,000175 \times 12,600 = 2,205,000

So,

a×b=2,205,000a \times b = 2,205,000

Next, since both aa and bb are greater than 175, they must be multiples of 175. Let’s express aa and bb as:

a=175xandb=175ya = 175x \quad \text{and} \quad b = 175y

where xx and yy are integers greater than 1 and HCF(x,y)=1\text{HCF}(x, y) = 1 (since the HCF of aa and bb is 175). Substituting these into the product equation:

(175x)×(175y)=2,205,000(175x) \times (175y) = 2,205,000

This simplifies to:

1752×xy=2,205,000175^2 \times xy = 2,205,000

30,625×xy=2,205,00030,625 \times xy = 2,205,000

Now, divide both sides by 30,625:

xy=2,205,00030,625=72xy = \frac{2,205,000}{30,625} = 72

So, x×y=72x \times y = 72. Now we need to find two numbers xx and yy such that:

  • x×y=72x \times y = 72
  • HCF(x,y)=1\text{HCF}(x, y) = 1

The pairs of integers that multiply to give 72 and have an HCF of 1 are:

  • (8,9)(8, 9)

Thus, x=8x = 8 and y=9y = 9. Therefore, the two numbers aa and bb are:

a=175×8=1,400a = 175 \times 8 = 1,400 b=175×9=1,575b = 175 \times 9 = 1,575

Thus, the two numbers are 1,400 and 1,575.

Would you like more details, or do you have any questions?

Here are 5 related questions:

  1. How do we find the HCF and LCM of two numbers manually?
  2. What is the significance of prime factorization in finding the HCF and LCM?
  3. Can two numbers have an HCF greater than 1 and still be co-prime?
  4. How does the product of two numbers relate to their HCF and LCM?
  5. What is the difference between the greatest common divisor and least common multiple?

Tip: If two numbers have a known HCF and LCM, their product will always equal the product of the HCF and LCM.

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Math Problem Analysis

Mathematical Concepts

Number Theory
Highest Common Factor (HCF)
Lowest Common Multiple (LCM)

Formulas

HCF × LCM = Product of the two numbers
a = 175x, b = 175y where HCF(a, b) = 175

Theorems

Relationship between HCF and LCM
Prime factorization to find coprime pairs

Suitable Grade Level

Grades 8-10