Which numbers are both factors of 80 and multiples of 10

Question

I can't answer the question

 what numbers are both factors of 80 and multiples of 10

I need help it's hard

 

 

Answer 1

write the factors of 80

1,80

2,40

4,20

5,16

8,10

{1,2,4,5,8,10,16,20,40,80}

write the multiples of 10

{0,10,20,30,40,50,60,70,80,...}

What numbers do the two sets have in common ?

10, 20, 40, and 80

Answer 2

Assuming multiples of 10 are greater than 10 (meaning we will not consider 1/10, 1/100, etc), then all multiples have a zero in the ones column such as 10, 20, 30, 40, etc.

 

If a number is a factor of 80, then 80 must be divisible by that number with no remainder.

 

Let's start with 10. 80/10 = 8 so 10 is one of the answers.

80/20 = 4 so 20 is another answer.

80 is not divisible by 3 so we will skip 30.

80/40 = 2 so we have another answer.

And finally 80/80 = 1

 

In summary, the answers are 10, 20, 40, and 80

Answer 3

10, 20, 40 are the answer.