Answer: When x=2 and z = 1, then the value of y =4.
Step-by-step explanation:
Given: y varies directly as x and z i.e. [tex]y\ \alpha \ xz[/tex]
[tex]y=k(xz)[/tex] (i) , where k is the proportionality constant.
Put Y=40 ,x =5 and z = 4, then we get
[tex]40=k(5\times4)\\\\\Rightarrow\ k=\dfrac{40}{20}\\\\\Rightarrow\ k=2[/tex]
Required equation: [tex]y=2(xz)[/tex] [Put value of k in (i)]
Now put x=2 and z = 1, then we get
[tex]y=2(2\times1)=2(2)=4\\\\\Rightarrow\ y=4[/tex]
Hence, when x=2 and z = 1, then the value of y =4.