Answer:
Q = 52.5
Step-by-step explanation:
given P is directly proportional to Q then the equation relating them is
P = kQ ← k is the constant of proportion
to find k use the condition Q = 30 when P = 40 , then
40 = 30k ( divide both sides by 30 )
[tex]\frac{40}{30}[/tex] = [tex]\frac{4}{3}[/tex] = k
P = [tex]\frac{4}{3}[/tex] Q ← equation of proportion
when P = 70 , then
70 = [tex]\frac{4}{3}[/tex] Q ( multiply both sides by 3 to clear the fraction )
210 = 4Q ( divide both sides by 4 )
52.5 = Q
