Question

120, 7. The value of yis directly proportional to the value of z. If y = 55 when z what is the value of v when = 60?

Answer 1

Since y is directly proportional to x, we can write the following relationship:

`y=k\cdot x`

where k is the constant of proportionallity. Then, k is equal to

`k=(y)/(x)`

By substituting y=55 and x=120, we have

`\begin{gathered} k=(55)/(120) \\ k=(11)/(24) \end{gathered}`

Therefore, our relationship is

`y=(11)/(24)x`

Finally, we know that x=60, then y is given by

`y=(11)/(24)(60)`

which gives

`\begin{gathered} y=(660)/(24) \\ y=27.5 \end{gathered}`

that is, when x=60, y is equal to 27.5.