Verified answer

7 times around =

7 • 2 π r =

7 • 2 • 22/7 • 3 =

44 • 3 =

132 inches

Sounds like a high school assignment, so I will try to explain rather than just give you the answer.

22/7 is an approximation of Pi

22/7 = 3.14285...

Pi = 3.14159...

The third decimal is wrong (the 2 should be a 1). So 22/7 is correct up to three significant digits: 3.14. If that is accurate enough, then you can use 22/7.

(below is an example, this is not the correct answer to the question!)

Suppose the exact answer to your question when you use Pi precisely (3.141592...) is 155.846 inch

Then when you use 22/7 you might find 156.221. But since 22/7 is only accurate up to 3 significant digits, you have to round it to three digits: 156. Note that if you round the exact answer, you will also get 156, so that answer is correct. Just it is only precise to the inch.

So if this answer is precise enough, you can use 22/7. If you need more precision, you need to use a more precise value for Pi.

As for the question with the post and the cord:

You can look it up with an internet search easily anyway, so I will state the formula: the circumference of a circle is:

2 x radius x Pi.

The cord will be wrapped around it 7 times...

The rest I leave up to you.

The radius of the pole is 3 inches so the diameter is twice that, or 6 inches.

The circumference of the pole is 6 * 22;/7, or (6*22)/7. That's one time around the pole. Exactly seven times around the pole is (6*22)/7*7, so the 7s fall out and you have 6*22 inches. Which is 142 in.

Oops. I mean 132 inches. (Did it in my head).

132 inches.

~Kevin.