city x has a population 5 times as great as the population of city y , which has a population twice as great as the population of city z . what is the ratio of the population of city x to the population of city z ?
"x = 5 y , y = 2 * z x : y , y : z 5 : 1 , 2 : 1 10 : 2 , 2 : 1 so , x : z = 10 : 1 ( e )"
multiply(5, const_2)