Question

Which of the following ratios is equivalent to 49:35?

Answer 1

The best way to find it is to reduce each ratio you work with to its
lowest terms,and see which ones are equal. To reduce a ratio to its
lowest terms, divide each number by their greatest common factor.

First, the one that you're trying to match:  49:35 .
The greatest common factor of 49 and 35 is 7 .
Divide each number by 7 . . .  7:5 . . . that's what you have to match.

7:4
Their greatest common factor is ' 1 '.
No help at all, and this one is not it.

14:25
Again, their greatest common factor is '1 '.
No help at all, and this one is not it.

21:15
Their greatest common factor is ' 3 '.
Divide both numbers by 3 . . . 7:5 .
That's it !

Answer 2

49=7*7
35=7*5
so 49:35=7*7:7*5=7:5
7:4 is not 7:5
14:25 also isn't 7:5
21:15=3*7:3*5=7:5
the answer is 21:15