The value of constant of variation "k" is
Solution:
Given that the direct variation is:
y = kx ----- eqn 1
Where "k" is the constant of variation
Given that the point is (5, 8)
To find the value of "k" , substitute (x, y) = (5, 8) in eqn 1
Thus the value of constant of variation "k" is k = 8/5 or 1.6
I hope this is correct and helps!
Since she need to mix 1 part concentrate with 10 part of water results to a juice to water ratio of 1 : 10.
Seems to be a geometric sequence which is found by

an=nth term
a1=first term
r=common ratio
first term is 0.75
it doubles each time so common ratio is 2

to find the nth term, input n and evaluate
example
to find the 20th term




just to find the kth term, input k for n in