Question

a,b,c,d lie on a straight line ab:bc=3:4 , ac:cd=2:1 find bc :ad??

Answer 1

ab:bc =3:4
if m is a constant then,
ab=3m, bc=4m
ac:cd=2:1
if n is another constant then,
ac=2n, cd=n
now ,
ab+bc=ac[because a,b,c,d is lie on a straight line]
or, 3m+4m=2n
or, 7m=2n
or, 7m/2=n
or, 3n=7×3m/2=21m/2
.'.bc:ad=bc:ac+cd =4m:2n+n
=4m:3n = 4m:21m/2=4:21/2
=8:21