Word Problem

Question

Town A and B are 6000 meters apart. Chris walked from A to B. In the first half of the time,

he walked at 80 meters per minute. He walked 70 meters per minute for the second half of

the time. How much time did he use to walk the entire distance?

Answer 1

Distance = rate x time, or time = distance/rate

 

For the first leg of the trip, the rate is 80 m/min

 

For the second leg of the trip, the rate is 70 m/min

 

He walked a total distance of 6000 m. If x represents the number of meters he walked in the first half of the trip, then 6000 - x is the number of meters walked for the second half. 

 

t₁ = x/80

 

t₂ = (6000 - x)/70

 

x/80 = (6000 - x)/70

 

70x = 480,000 - 80x

 

150x = 480,000

 

x = 3200 m

 

Therefore, t₁ = 3200/80 = 40 min

 

and t₂ = (6000 - 3200)/70 = 2800/70 = 40 min

 

Consequently, it took 40 + 40 = 80 min, or 1 hr 20 min to walk the entire distance