I got a few questions wrong and i would like some explanations on these question:
2. A pair of pants sells for $6 more than 75% of its price of the pants?
A.$12
B.$18
C.$20
D.$24
E.$36
Choice E is wrong.
4. What is the wall thickness, inches, of a tube with an outer diameter of 0.750 and an inner diameter of 0.625?
A.0.0625
B.0.125
C.0.625
D.0.6875
E.0.750
Choice B is wrong.
14.In the figure below. AC and BD are chords of a circle that intersect at point E (E point is not shown). AD is the diameter of this circle. If the measure of arc AB=40 degrees and <CED=60 degrees, what i the measure of <CAD?
A.60 degrees
B.45 degrees
C.30 degrees
D.40 degrees
E.15 degrees
Choice C is wrong.
24. A gear with 30 teeth revolving at 30 revolutions per minute is meshed with a second gear turning at 250 revolution per minute. How many teeth does this gear have?
A.36
B.25
C.15
D.30
E.24
Choice B is wrong.
8 answers
A pair of pants sells for $6 more than 75% of its price of the pants?
The question makes no sense.
#4 (A)
0.750 - 0.625 = 0.125
But that is the difference in the diameter. The wall thickness is the difference in radius: half that, or 0.0625
#14 (D)
since AB = 40°, <ADB = 20°
supplementary angle AED = 120°
The remaining angle of triangle AED is 40°
#24 ??
since the speed ratio is 250/30, the tooth ratio is 30/250 * 30 = 3.6
You sure that the speed is not 25.0 rpm? That would make the choice (A).
x = .75x + 6
.25x = 6
x = 24
4.
outer radius = .75/2 = .375
inner radius = .625/2 = .3125
so thickness of wall = .375-.3125 = .0625
14. no diagram
24.
Think of the teeth laid out linearly
For the first gear in 1 minute would cover 30x30 or 900 teeth
for the 2nd gear, let the number of teeth be x
then 250x = 900
x = 900/250 = 3.6 ????
mmmhhh? , typo? or flaw in my thinking
a gear with 3 teeth ????
4) .75/2 -.625/2 = .0625 (radius not diameter is used)
14) I get 40 (long, will elaborate later)
24) (30/250)(30) = 3.6