Question

if a:b = 3:4 ,b:c = 5:7 and the average of a, b, c is 21,what are the values of a, b, c​

Answer 1

Step-by-step explanation:

a:b3:4=15:20

b:c=5:7=20:28

a:b:c=15:20:28

a+b+c/3=21

a+b+c=63

15x+20x+28x=63

63x=63

x=1

then a=15,b=20,c=28

please mark as brainlist