The tail of a 1-mile long train exits a tunnel exactly 3 minutes after the front of the train entered the tunnel. If the train is moving 60 miles per hour, how many miles long is the tunnel?

Guest Jan 23, 2019

#1**+1 **

The tail (caboose as they used to have) starts 1 mile from the mouth of the tunnel....ti must travel THAT mile PLUS the length of the tunnel in 3 minutes

t = tunnel length

t + 1 = distance the caboose must travel in 3 minutes 3 minutes = 1/20 hr

(t+1) mile / 60 m/hr = 1/20 hr

t + 1 = 60/20

t = 2 miles long

ElectricPavlov Jan 23, 2019

#1**+1 **

Best Answer

The tail (caboose as they used to have) starts 1 mile from the mouth of the tunnel....ti must travel THAT mile PLUS the length of the tunnel in 3 minutes

t = tunnel length

t + 1 = distance the caboose must travel in 3 minutes 3 minutes = 1/20 hr

(t+1) mile / 60 m/hr = 1/20 hr

t + 1 = 60/20

t = 2 miles long

ElectricPavlov Jan 23, 2019