if line segment AC =120ft and the ratio of line AB:line BC=3:5, what is the length of line AB ?

Question

I set up the equation as x:120,3:5
x/120=3/5 3/120=360, 360 divided by 5=72
the answer in the book is 45, need help

Answer 1

It should have been x/120 = 3/8
which gives x = 45

notice AB:BC = 3:5
so AB could be 3 units, BC 5 units, making AC 8 units.