mensa

[daneswalk]

a 330 yard long train travelling at 30 mph enters a two mile long tunnel how long will elapse between the moment the front of the train enters the tunnel and the moment the end of the train clears the tunnel
thanks for any help

[sarumite]

I'm in a bit of a rush ... so hope this is right :

4.375 minutes.

Will look back shortly to double check.

[pquinlan]

From the first moment (front entering tunnel) it must travel 330 yards til the back end is just entering the tunnel, then 2 more miles til the back end exits the tunnel so it must travel 2 mile + 330 yards. 1 mile = 1760 yards, so 330 yards = 330/1760 = 0.1875 miles. So it travels 2.1875 miles @ 30 mph (or 0.5 mpm, miles per minute). Time = distance/speed so answer is 2.1875miles/0.5 mpm= 4.375 minutes or 4 mins 22.5 secs.

[sarumite]

It's a long time since my maths O level, so may be wrong!

The train will travel a total of 2mls 330yds from first entering the tunnel until leaving.

It is travelling each mile in two minutes.

Therefore total time taken = 4 + 330/1760 x2 = 4.375mins.

[sarumite]

Pleased to see that our end result is the same pquinlan!

[daneswalk]

thank you both for your answer my maths are not to bright i always say that there are some clever people on here thanks again