The answer would be 85, here's why
200/x=100/42.5
(200/x)*x=(100/42.5)*x
200=2.3529411764706*x
200/2.3529411764706=x
85=x
x=85
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.
Together their speed will be
.
If they drill together, they will spend
years.
Answer: it would have taken nearly 3 years.
700. To find out what number a value is ten times as much as, divide by 10.
10 / 1/5 = 50
hope this helps!