Question

Which is a common denominator for the numbers: 40 and 28

Question 1 options:

a)

1120


b)

40


c)

68


d)

1080

Answer 1

(a) 40 into 1120=28....28 into 1120=40 so 1120 is the denominator of 40&28

Answer 2

9514 1404 393

Answer:

a) 1120

Explanation:

If 28 and 40 are denominators of fractions, one way to find a common denominator is to simply multiply these values:

28×40 = 1120 . . . . a possible common denominator

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The Least Common Denominator is the least common multiple (LCM) of these denominator numbers. The LCM is their product, divided by their greatest common factor. Here, that factor is 4, so the least common denominator is 1120/4 = 280.