which of the following is a common denominator of 3/4 and 1/5

Question

A.35 B.20 C.15 D.30 please help me i really need help i will take anyone if you will help me that would be great

Answer 1

To find a common denominator, make a list of the multiples of each denominator:

For 4:

4

8

12

16

20

24

28

32

36

For 5:

5

10

15

20

25

30

35

Now, look down the lists until you find the first number that is in BOTH lists. That would be 20. So 20 is the LOWEST common denominator. In this case, they are asking for any common denominator, so keep looking. And you see that is the only one that is common for the range of the answers given (15 up to 35).

So the answer is 20.