A train needs 12 seconds to go through a 50 yard tunnel. The same train going at the same speed needs 20 seconds to go through a 170 yard tunnel. What is the length of the train?

Question

anonymous · Answer

anyone?

anonymous · Answer

6 yards

asnaseer · Answer

I believe you can solve this as follows:

1. call the length of the train L.
2. to go completely through a 50 yard tunnel it took 12s. this means it travelled 50+L yards in 12s.
3. to go completely through a 170 yard tunnel it took 20s. this means it travelled 120+L yards in 20s.

since it's speed was the same in both case, we get the equation:$$\frac{50+L}{12}=\frac{120+L}{20}$$solve this for L.

shane_b · Answer

Makes sense to me...except I believe it should be 170+L on the right equation.

asnaseer · Answer

oops - well spotted @Shane_B - thx :)

anonymous · Answer

can u help me with 1 more question?

shane_b · Answer

@asnaseer: Np :)

asnaseer · Answer

@azntiger627 just post each question in the usual maner and someone will come along to help. If I'm free I'll help as well.

anonymous · Answer

I posted one, mine is the third one down