P(at least 5 rolls until 1) = P(4 rolls are not 1) = 5/6 x 5/6 x 5/6 x 5/6 = 0.4823 (4sf)
Fewer than 7 rolls to get second 1 after first takes 3 rolls means second occurs on 4th, 5th or 6th roll
The probability of each of these is 1/6, 5/6 x 1/6 and 5/6 x 5/6 x 1/6 respectively.
P(second 1 on 4th, 5th or 6th roll) = 1/6 + 5/36 + 25/216 = 91/216 = 0.4213 (4sf)
Should be 67 or 113 if not then it’s probably 157
9514 1404 393
Answer:
- 113.0 cm²
- 2464.0 in²
- 95.0 ft²
Step-by-step explanation:
1. The area of a circle is given by the formula ...
A = πr² . . . . . where r is the radius
The radius is shown as 6 cm, so the area is ...
A = (3.14)(6 cm)² = 113.0 cm²
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2. The radius is shown as 28 in. We note that this is a number divisible by 7, so we choose 22/7 for π.
A = (22/7)(28 in)² = 2464 in² . . . . see comment
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3. The radius is half the diameter, so is 11/2 = 5.5 ft. Then the area is ...
A = (3.14)(5.5 ft)² = 95.0 ft²
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<em>Additional comment</em>
If you use a more exact value of π for problem 2, the area is 2463.0 in². If you use 3.14 as the value of π, the area rounds to 2461.8 in². For these values of pi (3.14 or 22/7), the answer is only good to about 3 significant digits. 2464 has more significant digits, so digits beyond the first 3 may be in error.
