Answer:
5 miles per hour
Step-by-step explanation:
Let the speed of Kelly is [tex]v_1[/tex] miles per hour and speed of Raul is v₂ miles per hour.
Since, speed = [tex]\frac{\text{Distance}}{\text{Time}}[/tex]
Kelly took 135 minutes to cover 90 miles from New York to Philadelphia.
∵ 1 minute = [tex]\frac{1}{60}[/tex] hours
∴ 135 minutes = [tex]\frac{135}{60}[/tex] = [tex]\frac{9}{4}[/tex] hours
v₁ = [tex]\frac{90}{\frac{9}{4}}[/tex]
= [tex]90\times \frac{4}{9}[/tex]
= 40 miles per hour
Raul took 153 minutes to cover the same distance as Kelly,
∵ 1 minute = [tex]\frac{1}{60}[/tex] hours
∴ 153 minutes = [tex]\frac{153}{60}[/tex] = [tex]\frac{51}{20}[/tex] hours
v₂ = [tex]\frac{90}{\frac{51}{20}}[/tex]
[tex]=90\times \frac{20}{51}[/tex]
= 35.29
≈ 35.3 miles per hours
v₁ - v₂ = 40 - 35.3
= 4.7
≈ 5.0 miles per hours
Therefore, Kelly is 5 miles per hours faster than Raul.
