walking with 3 / 5 of my usual speed , i miss the bus by 5 minutes . what is my usual time ?
"speed ratio = 1 : 3 / 5 = 5 : 3 time ratio = 3 : 5 1 - - - - - - - - 5 3 - - - - - - - - - ? è 15 answer : e"
multiply(divide(5, divide(5, 3)), 5)