Question

Find an equation of variation in which p varies jointly as q and t and p = 60 when q = 24 and t = 5. Find p when q = 12 and t = 4.

Answer 1

q = 24

Explanation:

given p varies jointly as q and t , the the equation relating them is

p = kqt ← k is the constant of variation

to find k , substitute the condition p = 60 when q = 24 and t = 5 into the equation

60 = k × 24 × 5

60 = 120k ( divide both sides by 120 )

`(60)/(120)` = k , that is

k =
`(1)/(2)`

p =
`(1)/(2)` qt ← equation of variation

when q = 12 and t = 4 , then

p =
`(1)/(2)` × 12 × 4 = 6 × 4 = 24