Question

In which of the following table, x and y vary directly:

x	27	45	54	75
y	81	180	216	225

Answer 1

`"x"_1/"x"_2=27/81=1/3`

`"x"_2/"y"_2=45/150=15/50=3/10`

`"x"_3/"y"_3=54/216=18/72=1/4`

`"x"_4/"y"_4=75/225=25/45=5/9`

`⇒"x"_1/"y"_1≠"x"_2/"y"_2 ≠"x"_3/"y"_3≠"x"_4/"y"_4`

x and y are not in direct variation.