Question

Q is directly proportional to √p Q = 21 when p = 9, the value of Q when p = 81 is *

1 point
63
64
56
67

Answer 1

We get Q=63 when p=81

Option A is correct.

Explanation:

We are given that
`Q \propto √(p)`

We can write it as
`Q=k√(p)`

Where k is constant of proportionality.

We are given Q = 21 when p = 9

Using this Q = 21 when p = 9 we can find value of k

`Q=k√(p)\\k=(Q)/(√(p) )\\k=(21)/(√(9) ) \\k=(21)/(3)\\k=7`

So, we get constant of proportionality k = 7

Now, Finding the value of Q when p = 81

We are given p=81, k=7, we need to find Q

Using the equation
`Q=k√(p)` we can find value of Q.

`Q=k√(p)\\Q=7√(81)\\Q=7* 9\\Q=63`

So, we get Q=63 when p=81

Option A is correct.