Given the speeds of each runner below, determine who runs the fastest. Debbie runs 10 feet per second.
Stephanie runs 131 feet in 10 seconds.
Jessica runs 1 mile in 440 seconds.
Ron runs 547 feet in 1 minute.

Debbie
Stephanie
Jessica
Ron

Debbie runs 9 feet per second: 9 ft/s

Jessica runs 1 mile  in 440 seconds: 414/50 ft/s = 207/25 ft/s = 8 7/25 ft/s

jesssica runs 131 feet in 10 seconds: since 1 mile = 5280 ft we have 1/470 mi/s = 5280/470 ft/s = 528/47 ft/s = 11 11/47 ft/s

ron runs 603 feet in 1 minute: 547 ft/min = 603/60 ft/s = 201/20 ft/s = 10 1/20 ft/s

Since:

11 11/47 > 10 1/20 > 9 > 8 7/25

Emily runs the fastest.

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

step-by-step explanation: