Each marble bag sold by yolanda's marble company contains 8 orange marbles for every 5 yellow marbles.
if a bag has 40 yellow marbles, how many orange marbles does it contain?

64.

Step-by-step explanation:

By proportion  to number of orange marbles =  (40 / 5) * 8

=  320 / 5

= 64 .

answer: 204

step-by-step explanation:

we are told that the revenue is

x⋅(4080−10x)=−10x^2+4080x

this is a quadratic function, so to maximize it we should find the x-value of its vertex. recall that the x-value of the vertex of the parabola ax^2+bx+c is given by the formula −b/2a.

so in this case, we have a=−10 and b=4080, so the x-value of the vertex is

−b/2a= −(4080)/2(−10)=204