Which is not in proportion a) 2 : 4 = 3 : 6 b) 1 : 3 = 3 : 9 c) 4 : 6 = 3 : 2 d) 5 : 1 = 10 : 2

C

Step-by-step explanation:

(a)

2 : 4 (divide both values by 2)

= 1 : 2

3 : 6 (divide both values by 3)

= 1 : 2

Thus 2 : 4 = 3 : 6

(b)

3 : 9 (divide both values by 3)

= 1 : 3

Thus 1 : 3 = 3 : 9

(c)

4 : 6 (divide both values by 2)

= 2 : 3 ≠ 3 : 2

(d)

10 : 2 (divide both values by 2)

= 5 : 1

Thus 5 : 1 = 10 : 2