SOLUTION: Can you help me solve for variation: n varies directly as q, and n=39 when q=3. Find n when q =8.

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Question 278339: Can you help me solve for variation: n varies directly as q, and n=39 when q=3. Find n when q =8.
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
n varies directly as q.
n = 39 when q = 3
find n when q = 8

n varies directly as q means that n = k*q

this means that:

39 = k*3

divide both sides of this equation by 3 to get:

k = 13

now that you have the value of k, you can solve for finding n when q = 8

you get:

n = k*q becomes n = 13*8 which becomes n = 104

in a direct variation problem, the ratio between n and q remains the same.

this means that n1 is to q1 as n2 is to q2.

in formula terms, this would be n1/q1 = n2/q2

in your problem, this becomes:

39/3 = 104/8

cross multiply and you get 39*8 = 3*104 which becomes 312 = 312 confirming that the ratio is the same between the 2 numbers of n/q.