abooogie17 abooogie17
  • 03-07-2017
  • Mathematics
contestada

A test driver has to drive a car on a 1-mile track for two rounds in a way, that his average speed is 60 mph. On his first round his average speed is 40 mph. How fast does he need to drive, to get the right speed average?

Respuesta :

musiclover10045
musiclover10045 musiclover10045
  • 03-07-2017

(40+x)/2=60

40 +x = 120

x = 80


check :

40+80 = 120

120/2 = 60

 so his second round needs to be 80 mph

Answer Link

Otras preguntas

Which equation has the same y-intercept as y=4x-3?a. y-3=x              b. y=8x+3    c. 3-y=4x      d. y=-3+8xWhich of the following is the equation of the line
find an equivalent expression without parentheses -(50x-15y+15)=
Prove that (x^5)-(x^2)+2x +3=0 has at least one real root. Prove that x=cosx has at least one solution.
Which equation has the same y-intercept as y=4x-3?a. y-3=x              b. y=8x+3    c. 3-y=4x      d. y=-3+8xWhich of the following is the equation of the line
(10y^3+20y^2+55y)/5y
Can someone use the word delta in a sentence
how is mass transit in cities a possible solution tk urban air pollution?
Can someone use the word delta in a sentence
what is the answer for (20,8),(9,16) ?
Find Domain of the functionsquare root of (x-8)/x(x-9)