Question

The variable z is directly proportional to x, and inversely proportional to y. When x is 7 and y is 7, z has the value 2. What is the value of z when x= 10, and y= 12

Answer 1

Answer:

z = $\frac{5}{3}$

Step-by-step explanation:

Given z is directly proportional to x and inversely proportional to y then the equation relating them is

z = $\frac{kx}{y}$ ← k is the constant of proportionality

To find k use the condition x = 7, y = 7 and z = 2

k = $\frac{zy}{x}$ = $\frac{2(7)}{7}$ = 2

z = $\frac{2x}{y}$ ← equation of proportionality

When x = 10 and y = 12, then

z = $\frac{2(10)}{12}$ = $\frac{20}{12}$ = $\frac{5}{3}$