2 pounds = $3.96
4 pounds = $3.96 x 2
4 pounds = $7.92
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Answer: $7.92
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You didn't include the options, so whichever one looks like x=(12.53+11.86)3.19 or something similar. You need to add the amount of gallons he bought, then multiply them by the cost per gallon, which will most likely be set equal to a variable.
Answer:
B. 6√2
Step-by-step explanation:
We can use the Pythagorean Theorem to solve this out. The Pythagorean Theorem states that for any right triangle with the shortest sides (called legs) as a and b and the longest side (called the hypotenuse) as c:
a² + b² = c²
Here, a = b = 6, so:
6² + 6² = c²
36 + 36 = c²
72 = c²
c = √72 = 6√2
Now, we see the answer is B.
However, there's a trick to solving these kinds of problems. Notice that DEF is both an isosceles triangle and a right triangle. We call these 45-45-90 triangles because those are the angles of the triangle.
One characteristic of these types of triangles is that their leg to leg to hypotenuse ratio is 1 : 1 : √2, always. We could apply that here. We see that the legs are 6, so we could find the hypotenuse simply by multiplying 6 by √2, and we would get 6√2, which is exactly the value we obtained above.
Thus, the answer is B.
Answer: the eastbound train had travelled 12 miles
Explanation: using Pythagoras theorem, we know that
X^2 = a^2 + b^2
Where ^ stands for raised to power.
Let
a stand for the train going towards North and
b stands for the train going towards east.
X stands for the total distance between train a and b = 20 miles.
By Pythagoras rule
X^2 = a^2 + b^2
20^2 = 16^2 + b^2
400 = 256 + b^2 so that
b^2 = 400 - 256 = 144
b = √144
b = 12 miles.
