# Find an equation of combined variation where a varies directly as b and inversely as c. One set of values is a = 4, b = 12, and c = 9. Find a when b = 7 and c = 3.

Combined equation is

Step-by-step explanation:

a varies directly as b and  inversely as c.

This can be written as

a =

a =  kb

where k is the proportionality constant

-------------------------------------(1)

Now lets find the k value bu substituting the given a, b,c values

36 =  12 k

k = 3

Thus the eq(1) becomes

Let us now find the value of a  when b=7  and c = 3

a = 7

## Related Questions

An assembly consists of two mechanical components. Suppose that the probabilities that the first and second components meet specifications are 0.89 and 0.84. Assume that the components are independent. Determine the probability mass function of the number of components in the assembly that meet specifications. X = number of components that meet specifications. Round your answers to four decimal places (e.g. 98.7654).

P(X = 0) = 0.0176

P(X = 1) = 0.2348

P(X = 2) = 0.7476

Step-by-step explanation:

Because there are 2 mechanical components you have 3 differents scenarios:

1. The 2 components dont meet the specification (X = 0)

2. 1 of the 2 component doesnt meet the specification (X = 1)

3. The 2 components meet the specification. (X = 2)

P(A) = 0.89

The probability that A doesnt meet the specification is 1- P(A) = 0.11

P(B) = 0.84

The probability that A doesnt meet the specification is 1- P(B) = 0.16

Then using those probabilities to determine the probabilities of each scenario you get:

1. The 2 components dont meet the specification

P (X = 0) = (1 - P(A)) * (1- P(B))

P (X = 0) = 0.11 * 0.16 = 0.0176

2. 1 of the 2 component doesnt meet the specification (X = 1)

P (X = 1) = P(A)*(1- P(B)) + P(B)*(1 - P(A)) /// (The probability that A meets specification and B doesnt or B that meets specification and A doesnt)

P (X = 1) = 0.89*0.16 + 0.84*0.11 = 0.2348

3. The 2 components meet the specification. (X = 2)

P(X = 2) = 0.89*0.84 = 0.7476

Gayle is making fruit punch that consists of 2 quarts of juice and 1 quart of soda water. How much soda water does she need if she has 5 quarts of juice?

Gayle would need 2 and a half quarts of soda water
Gale will need to have two half quarts of soda water

What is the curse of bambino

It is a myth/superstition, some people took it seriously but some thought it was a lie
The curse of the bambino is just a myth...

Jaime has 16 grapes. Samantha has 20 grapes. Each girl eats of her grapes. Which statement is true? A. Jaime ate more grapes than Samantha did.

B. Samantha ate more grapes than Jaime did.

C. Jaime and Samantha ate an equal number of grapes.