Question

A quantity b varies jointly with c and d and inversely with e. When b is 18, c is 4, d is 9, and e is 6. What is the constant of variation?

1/12
1/3
3
12

Answer 1

The answer is C. 3

Explanation:

Answer 2

b
`\alpha`
`(cd)/(e)`
b=
`k (cd)/(e)`
Where k is a constant of proportionality.
b=18, c=4,d=9, e=6
Finding the value f k,
18=
`(k*4*9)/(6)`
6k=18
k=3
The equation then is;
b=
`(3cd)/(e)`
The constant of variation=3