Two numbers are in the ratio 3 : 8. If 8 is added to each number, then the ratio becomes 1: 2. If 4 is subtracted from each number, then the ratio will become:

Correct option is C

Given:
​Two numbers are in the ratio 3 : 8. If 8 is added to each number, then the ratio becomes 1: 2.
Solution:​
Let the numbers be 3x and 8x. 

$$\frac{3x + 8}{8x + 8} = \frac{1}{2}\\$$

6x + 16 = 8x+ 8 
2x = 8
x= 4

The numbers are $$3 \times 4$$​ = 12 and  $$8 \times 4$$​ = 32

The ratio when 4 is subtracted from each number:

= 12 - 4 : 32 - 4
= 8 : 28
= 2 : 7
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