Explanation:
Kadisha's method works because 15% is 3 times 5%, and both amounts are computed on the amount of the bill before tax is added.
9x+14x+4x+90 = 360
27x = 270
x = 10
<F = 14x = 14(10) = 140
The answer is A) 7x103 is 3.5 times larger than 2x103
The ground, the building, and the ladder form a right triangle, in which
the leaning ladder is the hypotenuse.
For the angle between the ladder and the ground, the 4-ft along the ground
is the side adjacent to the angle, and the 7-ft ladder is the hypotenuse.
(adjacent side) / (hypotenuse) = cosine of the angle.
Cosine(a) = 4/7 = 0.57143... (rounded)
Angle 'a' = <em>55.15 degrees</em> (rounded)