The length of AE is 
Explanation:
From the figure, we can see that the two triangles ΔAED and ΔACB are similar. Thus, the legs of the triangle are proportional to each other.
Thus, we have,

Substituting the values of the sides from the image, we get,

Multiplying both sides of the equation by 6, we get,

Multiplying, we have,

Thus, the length of AE is 
The answer is 2 hours because from 5 to 7 the temperature was raising <span />
16 gal... 480 mi
1 gal... 480/16 = 30 mi
9 gal.. 30*9 = 270 mi
The value has decreased because the amount he gets in Canadian dollars has decreased for the exact same amount he has in yuan.
I.e. Before: 12000/6.64 = 1807.23 Canadian dollars
Present: 12000/6.78 = 1769.91 Canadian dollars