The answer to Q1 along with an explanation is shown in the picture;
Having a look at all the questions, they are all essentially the same type so can all be solved similarly;
So by following the method and explanation, you should be able to do the rest of the questions.
4/1 x 3/2 = 12/2
6/9 x 1/7 = 6/63
5/6 x 2/1 = 10/6
8/3 x 1/6 = 8/18
8/1 x 5/8 = 40/8
It’s not my answer but I think it’s correct!
(C) jasmyne is the one with the proportinal relationship