Answer:
5:8
Step-by-step explanation:
By question it's given that ,
[tex]\implies a:b = 1:2 [/tex]
Let us suppose that the common ratio is x , therefore the Numbers ,
[tex]\implies a = 1x [/tex]
[tex]\implies b = 2x [/tex]
And we need to find the value of ,
[tex]\implies (3a + b): (4a + 2b ) \\\\\implies (3 * x + 2x ) : (4*x + 2*2x ) \\\\\implies (3x + 2x):(4x+4x)\\\\\implies 5x : 8x \\\\\implies 5:8 [/tex]
Hence the required answer is 5:8 .