Answer :
Explanation :
find the HCF of 36 and 20
20 = 1, 2, 4, 5, 10, 20
36 = 1, 2, 3, 4, 6, 9, 12, 18, 36
comparing,we can see that 4 is the highest common factor of 20 and 36
now , Simplifying
thus, 9:5 and 36:20 are equal.