Answer:
.2
Step-by-step explanation:
When you do 64/80 you get 0.8 which means that the percent decrease is .2
He can either measure the third side length, apply the Pythagorean theorem to find the height of the triangle, and then calculate the area, or he can find the measure of the included angle between the known side lengths and use trigonometry to express the height of the triangle and then determine the
area of the triangle
Answer:
The value of x would be
or 
Step-by-step explanation:
Given,
x tons of 10% gravel G mixture is mixed with y ton of 2% gravel G to obtain 5% gravel mixture,
Thus, gravel G in x ton + gravel in y ton = gravel G in the resultant mixture,
⇒ 0.1x + 0.02y = 0.05(x+y),
0.1x - 0.05x = 0.05y - 0.02y
0.05x = 0.03y

Now, resultant mixture is z ton,
i.e. 

From equation (1),



