Question

a certain number has exactly eight factors including 1 and itself two of its factors are 21 and 35 the number is

Answer 1

Given that a certain number has exactly eight factors including 1 and itself two of its factors are 21 and 35.

Since 21 is factor of that number then factors of 21 will also be factors of the required number.

factors of 21 are 1,3,7,21.

So we found two more factors 3 and 7.

Since 35 is factor of that number then factors of 35 will also be factors of the required number.

factors of 35 are 1,5,7,35.

So we found one more factor "5" which was not on the list.

Now LCM of 21 and 35 will also be a factor which is 105.

Let's collect all factors. we get:

{1,3,5,7,21,35,105}

they are 7 in total so we need one more factor which can be multiple of 3 and 5 which is 15

New list is {1,3,5,7,15,21,35,105}

Now we have total 8 numbers in the list so final answer is 105.

Answer 2

Step-by-step explanation:

first lublana what gave that is correct