Given that, A = B/4
∴ A/B = 1/4 or A : B = 1 : 4
Also, B = C/2 or B/C = 1/2 or B : C = 1 :2
Now, we have A : B = 1 : 4; B : C = 1 : 2

Correct Option: C

Given that, A = B/4
∴ A/B = 1/4 or A : B = 1 : 4
Also, B = C/2 or B/C = 1/2 or B : C = 1 :2
Now, we have A : B = 1 : 4; B : C = 1 : 2
A : B : C = ( 1 x 1 ) : ( 1 x 4 ) : ( 2 x 4 )
= 1 : 4 : 8

Given that 0.8 x A = 0.09 x B
⇒ A/B = 0.09/0.8 = 9/80

Correct Option: A

Given that 0.8 x A = 0.09 x B
⇒ A/B = 0.09/0.8 = 9/80
∴ A : B = 9 :80

Let 1/x = 2K, 1/y = 3K and 1/z = 5K
Then, x = K/2, Y = K/3 and z = K/5
∴ x : y : z = K/2 : K/3 : K/4

Correct Option: D

Let 1/x = 2K, 1/y = 3K and 1/z = 5K
Then, x = K/2, Y = K/3 and z = K/5
∴ x : y : z = K/2 : K/3 : K/4
= 1/2 : 1/3 : 1/5
= 15 : 10 : 6

Let a/3 = b/8 = K
Then, a = 3K, b = 8K
∴ (a + 3) / (b + 8) = (3K + 3) / (8K + 8)

Correct Option: A

Let a/3 = b/8 = K
Then, a = 3K, b = 8K
∴ (a + 3) / (b + 8) = (3K + 3) / (8K + 8)
= [3( K + 1)] / [8(K+1)] = 3/8
∴ ( a + 3 ) : (b + 8) = 3 : 8

1/2 of A = 2/5 of B = 1/3 of C
1/2 x A = 2/5 x B = 1/3 x C
Let A/2 = 2B/5 = C/3 = K
Then, A = 2K, B = 5K/2, C = 3K

Correct Option: A

1/2 of A = 2/5 of B = 1/3 of C
1/2 x A = 2/5 x B = 1/3 x C
Let A/2 = 2B/5 = C/3 = K
Then, A = 2K, B = 5K/2, C = 3K
⇒ A: B : C = 2k : 5k/2 : 3k
∴ A: B : C = 4 : 5 : 6