When building the Channel, the English and French each started drilling on opposite sides of the English Channel. The two sectio
ns became one in 1990. The French used more advanced drilling machinery than the English. Suppose the English could drill the Channel in 6.2 years, and the French could drill in 5.8 years, how long would it have taken the two together?
Suppose the English could drill the Channel in 6.2 years, then they drill with speed km per year, where L is the length of the English Channel. If the French could drill in 5.8 years, then their speed of drillling is km per year.
In total there are 12 marbles because 6+4+2=12 and it says you pick 2 marbles from the hat so you subtract 12-2 and that gives you 10 and it says the marbles aren't returned so therefore you are left with 10 marbles. Hope this helps .