Answer:
y = 12
Step-by-step explanation:
If y varies directly as x and z;
y ∝ xz
y = kxz .......1
Where k is the constant of Proportionality;
y=8/3 when x=1 and z=4
Making k the subject of formula and substituting the given values.
k = y/xz
k = (8/3)/(1×4)
k = (8/3)/4
k = 2/3
when x=6 and z=3;
From equation 1;
y = kxz
And;
k = 2/3
x = 6
z = 3
Substituting the values;
y = 2/3 × 6 × 3
y = 12
