Answer:
The speed of Mr Solberg's scooter when there is no wind is 35 miles per hour
Step-by-step explanation:
The given parameters are;
The time Mr. Solberg rides his scooter and cover 3 miles against the wind = The time Mr. Solberg rides his scooter and cover 4 miles with the wind
The speed of the wind = 5 miles per hour
Let v, represent the speed of Mr Solberg's scooter when there is no wind, we have;
Time = Distance/Speed
Mr Solberg's speed against the wind = v - 5
Mr Solberg's speed with the wind = v + 5
The distance covered at a given time, while riding against the wind = 3 miles
The distance covered at the same time, while riding with the wind = 4 miles
The time in both instances are therefore 3/(v - 5) = 4/(v + 5)
From which we have;
3 × (v + 5) = 4 × (v - 5)
3·v + 15 = 4·v - 20
20 + 15 = 4·v - 3·v
4·v - 3·v = 20 + 15
v = 35
The speed of Mr Solberg's scooter when there is no wind = v = 35 miles per hour.