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505-555 (Easy)|   Geometry|      
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In the figure above, a circular hoop is rolling along a flat Updated on: 17 Sep 2013, 01:18
Originally posted by fozzzy on 17 Sep 2013, 01:09.
Last edited by Bunuel on 17 Sep 2013, 01:18, edited 1 time in total.
Edited the question and the tags.
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E
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Question Stats:

80% (01:13) correct 20% (01:33) wrong based on 127 sessions

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In the figure above, a circular hoop is rolling along a flat surface in a straight line. If point A touches the surface at 25-inch intervals, then the radius of the hoop is approximately

A) 8 in
B) 7 in
C) 6 in
D) 5 in
E) 4 in
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E
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In the figure above, a circular hoop is rolling along a flat Updated on: 03 Aug 2015, 13:42
Originally posted by Bunuel on 17 Sep 2013, 01:17.
Last edited by ENGRTOMBA2018 on 03 Aug 2015, 13:42, edited 1 time in total.
Corrected the typo.
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In the figure above, a circular hoop is rolling along a flat surface in a straight line. If point A touches the surface at 25-inch intervals, then the radius of the hoop is approximately

A) 8 in
B) 7 in
C) 6 in
D) 5 in
E) 4 in

We are basically given that the circumference of the circle is 25 inches --> \(2\pi{r}=25\) --> \(r=\frac{25}{2\pi}\approx{\frac{25}{6.28}}\approx{4}\).

Answer: E.
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In the figure above, a circular hoop is rolling along a flat 03 Aug 2015, 13:30
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Bunuel

In the figure above, a circular hoop is rolling along a flat surface in a straight line. If point A touches the surface at 25-inch intervals, then the radius of the hoop is approximately

A) 8 in
B) 7 in
C) 6 in
D) 5 in
E) 4 in

We are basically given that the circumference of the circle is 24 inches --> \(2\pi{r}=25\) --> \(r=\frac{25}{2\pi}\approx{\frac{25}{6.28}}\approx{4}\).

Answer: E.
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Bunuel! I think you meant 25 inch not 24 (bold part). Thanks!
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In the figure above, a circular hoop is rolling along a flat 03 Aug 2015, 13:43
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Konstantin1983
Bunuel

In the figure above, a circular hoop is rolling along a flat surface in a straight line. If point A touches the surface at 25-inch intervals, then the radius of the hoop is approximately

A) 8 in
B) 7 in
C) 6 in
D) 5 in
E) 4 in

We are basically given that the circumference of the circle is 24 inches --> \(2\pi{r}=25\) --> \(r=\frac{25}{2\pi}\approx{\frac{25}{6.28}}\approx{4}\).

Answer: E.
Bunuel! I think you meant 25 inch not 24 (bold part). Thanks!
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Thanks, post updated.
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In the figure above, a circular hoop is rolling along a flat 03 Aug 2015, 18:53
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If Point A on the hoop leaves a mark every 25 inches, the hoop has a Circumference of 25. The formula for Circumference is 2 pi r. Since the question is asking for the radius, we can calculate it. 25 = 2 pi r ==> 12.5 = pi r ==> 12.5/pi = r

If we approximate pi as 3, r is approximately 4.

Correct answer is E
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In the figure above, a circular hoop is rolling along a flat 07 Aug 2017, 21:00
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