Answer:
and

Explanation:
We are given that some fractions
We have to find the pair of fractions which are proportional
We know that if fraction
are proportional
Then , product of a and d is equal to product of b and c.
In

Product of 14 and 42

Product of 35 and 21

Hence,
and
are not proportional.
2.

Product of 6 and 21

Product of 7 and 16

Hence, they are not proportional.
3.
and

Product of 36 and 9

Product of 54 and 6

Hence, the pair of fractions are proportional.
4.
and

Product of 21 and 25

Product of 36 and 14

Hence, pair of fractions are proportional.