Question

For nonzero numbers x,y, and z, 3x=4y and 12y=5z. What is z/x?

Answer 1

from 3x = 4y ---> x = 4y/3
from 12y = 5z --> z = 12y/5

so z/x = (12y/5) / (4y/3)
= (12y/5)(3/4y)
= 9/5