Answer:
y = 10
Step-by-step explanation:
Given y varies jointly as x and z then the equation relating them is
y = kxz ← k is the constant of variation
To find k use the condition y = 20 when x = 4 and z = 3 , then
20 = k × 4 × 3 = 12k ( divide both sides by 12 )
= k , that is
k =
y = xz ← equation of variation
When x = 2 and z = 3 , then
y = × 2 × 3 = 5 × 2 = 10