Question

Formula for the distance (d) is given by d = rate*time. For example if you are traveling at 60 mph for 3 hours the distance traveled is 180 (=60*3). Assuming Mary is traveling at 50 mph and Jim is traveling at 60 mph, how long does Jim have to travel in order that the distance between Mary and Jim is greater than or equal to 100 miles? NOTE: After one hour Jim is 10 miles aheadAssume Mary and Jim leave at the same time, are traveling in the same direction on parallel tracks11 hours9 hours10 hours8 hours

Answer 1

Explanation:

Distance covered by the particle is given by:

Distance (d) = rate (v) × time (t)                

Speed of Mary, v₁ = 50 mph

Speed of Jim, v₂ = 60 mph

It is assumed that, Mary and Jim leave at the same time. After one hour, Jim is 10 miles ahead.

Distance travelled by Jim, d₁ = (60t + 10)

Distance travelled by Mary, d₂ = 50t

The distance between Mary and Jim is greater than or equal to 100 miles.

$60t+10-50t\ge100$

$10t\ge90$

$t\ge9\ h$

So, Jim takes is 9 hours more than Mary to cover same distance. Hence, this is the required solution.