Find a:b:c
a:b=5:3 and b:c=6:5

a:b can be written as 10:6 which means a:b:c = 10:6:5.

10:6:5

Step-by-step explanation:

a:b=5:3 means  a=5*x ,  b=3*x  =>  a:b= (5*x) : (3*x)   (1)

b:c=6:5  means  b=6*y, c=5*y  (2)

So b=3x=6y => x= 2y => lets rewrite (1) as follows below

a:b= (5*2*y):(3*2*y)=(10*y):(6*y)=10:6  (3)

So from (2) and (3) follows => a:b:c= (10*y): (6*y): (5y)= 10:6:5

answer: 1, 3 and 5 are correct

step-by-step explanation: