Question

if a:b=3:4,b:c=5:7,find a:b:c?

Answer 1

a:b=3:4
b:c=5:7
take the LCM of B that's 4 and 5=20
a:b=3×5:4×5
b:c=5×4:7×4
a:b:c=15:20:24

Answer 2

20:15:12 is correct answer