Answer:
t = 5
Step-by-step explanation:
Given r varies directly as t³ then the equation relating them is
r = kt³ ← k is the constant of variation
To find k use the condition r = 54 when t = 3 , then
54 = k × 3³ = 27k ( divide both sides by 27 )
2 = k
r = 2t³ ← equation of variation
When r = 250 , then
250 = 2t³ ( divide both sides by 2 )
125 = t³ ( take cube root of both sides )
[tex]\sqrt[3]{125}[/tex] = t , that is
t = 5
