30 = 3/5....................equation (1)
60 = x.............................equation (2)
equation (1) divided by equation (2)
30 / 60 = 3/ 5 / x
by solving
1 / 2 =3 / 5 x
cross multiplication
5 x = 6
x = 6/ 5..................equation (3)
put x in equation ( 2)
60 % = 6 / 5
proof multiply equation (1) by 2
30 * 2= 3 / 5 * 2
60 = 6 / 5 .
answer is proved