Which one of the following is a proportion?
a) 32: 64 = 1 : 2
b) 1:2 =3:4
c) 22 : 34 = 2 : 2
d) 15: 5 = 7: 8
a)
In a proportion,
Product of means = Product of extremes
Consider 32: 64 = 1 : 2 ,
Product of means = Product of extremes
=> 64×1=32×2
=> 64 = 64
So, answer is 32: 64 = 1 : 2