If n and t are positive integers, what is the greatest prime factor of the product nt ? (1) The greatest common factor of n and t is 5. (2) The least common multiple of n and t is 105.

Respuesta :

Answer:

Greatest prime factor of [tex]nt[/tex] is 7.

Step-by-step explanation:

Given that

Two positive integers are [tex]n[/tex] and [tex]t[/tex].

(1) Greatest Common Factor or HCF of [tex]n[/tex] and [tex]t[/tex] is 5.

(2) Least Common Multiple or LCM of [tex]n[/tex] and [tex]t[/tex] is 105.

To find:

The greatest prime factor of the product [tex]nt[/tex] = ?

Solution:

First of all, let us learn about a property of HCF and LCM of two numbers.

The product of two numbers [tex]p[/tex] and [tex]q[/tex] is equal to the product of their HCF and LCM.

[tex]p \times q =LCM\times HCF[/tex]

Using this property for the given numbers:

[tex]n\times t =5\times 105\\OR\\nt =5\times105[/tex]

Now, let us make prime factors of [tex]5 \times 105[/tex] to find the greatest of the prime factors.

[tex]5\times 105 = 5\times 5 \times 21 =5\times 5 \times 3 \times \bold{7}[/tex]

So, the prime factors of [tex]5 \times 105[/tex] are 5, 5, 3 and 7.

Greatest prime factor of [tex]nt[/tex] is 7.