1. Given that Y varies directly as X and inversely as Z , the relationship can be written as:
Y=k\times\frac{X}{Z}
2. Using the initial conditions Y = 9 , X = 12 , and Z = 4 , we can solve for k :
9=k\times\frac{12}{4}
9 = 3k
k = 3
3. Now substitute X = 45 , Z = 5 , and k = 3 into the equation:
Y=3\times\frac{45}{5}
Y = 3 \times 9
Y = 27
Answer: Y=27