Question

if a:b=c:d=e:f=1:2,then(3a+5c+7e):(3b+5d+7f) is

Answer 1

(3a+5c+7e):(3b+5d+7f)
= (3 x 1+5 x 1 + 7 x 1): ( 3 x 2+ 5 x 2+ 7x 2)
= 15 + ( 6 +10+ 14)
=15+20
= 35

Answer 2

a:b=1:2
a=b/2   similarly c=d/2  & e=f/2

(3a+5c+7e)/3b+5d+7e
(3b+5d+7f)/2
------------------- = 1/2
3b+5d+7f