Question

if a:b=5:7and b:c=14:15,find a:c

Answer 1

a:b=5:7
a/b=5/7...(1)
b:c=14:15
b/c=14/15...(2)
Multipling eq.(1) and(2)
(a/b)×(b/c)=(5/7)×(14/15)
a/c=2/3
a:c=2:3