Im going to start with my example for a. So you have to figure out how you can get to 8 from 2. So that would be 2*4=8. And whatever you do to the top, you must also do to the bottom. So for the top we multiplied by 4, so we also have to multiply the bottom by 4. So that would be 26*4=104. So your total/answer would be 8 teachers= 104 students. In another way, for f. it would be the same but you have to divide instead since 9 is bigger than 3. Hope this helped ! :)
since both of these have a common multiply of 6 (3 x 2 = 6 and 6 already being there for the larger one) you would multiply both the 1 and the 3 by 2 so it's easier to solve, and you get 2/6.
