Answer:
He completes a lap running in 3 minutes, and walking in 4 minutes.
Step-by-step explanation:
This question can be solved by a system of equations.
I am going to say that:
x is the time needed to complete a lap running.
y is the time needed to complete a lap walking.
He requires 40 minutes to do 4 laps running and 7 laps walking.
This means that:
[tex]4x + 7y = 40[/tex]
[tex]4x = 40 - 7y[/tex]
He requires 18 minutes to do 2 laps running and 3 laps walking.
This means that
[tex]2x + 3y = 18[/tex]
Multipluing everything by 2
[tex]4x + 6y = 36[/tex]
Since [tex]4x = 40 - 7y[/tex]
[tex]40 - 7y + 6y = 36[/tex]
[tex]y = 4[/tex]
And
[tex]4x = 40 - 7y[/tex]
[tex]4x = 40 - 7*4[/tex]
[tex]4x = 12[/tex]
[tex]x = \frac{12}{4}[/tex]
[tex]x = 3[/tex]
He completes a lap running in 3 minutes, and walking in 4 minutes.