Problema Solution
A tunnel connects to the United Kingdom an France by a railway under the English Channel. The British started tunneling 2.5 months before the French with an average of .63 km per month. The French averages .47 km per month. When the two sides met they had travele 37.9 km. How many kilometers of the tunnel di each country build. If the French started tunneling on February 28, 1988, approximately when id the two sides meet.
Answer provided by our tutors
Let t = months tunneling by the British
then
(t-2.5) = months tunneling by the French
;
Write a distance equation: Dist = speed * time
:
British dist + French dist = 37.9
.63t + .47(t-2.5) = 37.9
:
.63t + .47t - 1.175 = 37.9
:
.63t + .47t = 37.9 + 1.175
:
1.1t = 39.075
t =
t = 35.52 months
then
35.52 * .63 = 22.38 km Built by the British
And
(35.52-2.5) * .47 = 15.52 km built by the French
:
French construction time 35.52 - 2.5 = 33.02 months
:
Using an average of 30.4 days per month: 30.4 * 33.02 ~ 1004 days
:
1004/365 = 2.75 yrs, or 2 yrs & 9 months
:
Starting it Feb 28, 1988, then it would be about Dec 1, 1990