Check all of the following cartesian products in which the following elements belong:
a= {1,3,5}
b= {2,3}
1) (1,2)
[] b x a
[] b x b
[] a x b
[] a x a
2) (3,1)
[] b x a
[] b x b
[] a x b
[] a x a
3) (1,1)
[] b x a
[] b x b
[] a x b
[] a x a
4) (3,3)
[] b x a
[] b x b
[] a x b
[] a x a