Explain how estimation helps you to place the decimal point when multiplying 3.9 times 5.3

1 answer:

8 0

I see it like this: we mupliply almost 4 by a little more then 5, so the result will be around 20 (4*5=20) : so the decimal point must be after the 20 (and it is, the result is 20.67

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The cone pictured has a surface area of ______ square centimeters. (Use 3.14 for π.)

Marina86 [1]

Assuming that the units are in cm
Given,

Diameter of the cone = 12 cm

Using the above, the radius of the cone can be determined, which is half the diameter of the cone

∴ Radius of the cone (r) = 12/2 = 6 cm
Height of the cone (h) = 7 cm

Using the above, slant height (s) = √(r² + h²) = √(6² + 7²) = √36 + 49 = √85 = 9.22 cm

π = 3.14

Now using the above values, we can calculate the total surface area of the cone.
Total surface area of the cone (A) = Lateral surface area of the cone (L) + Base surface area of the cone (B)

Lateral surface area of the cone (L) = π r s = 3.14 x 6 x 9.22 = 173.70 cm²
Base surface area of the cone (B) = π r² = 3.14 x 6² = 113.04 cm²

Total surface area of the cone = L + B = 173.70 + 113.04 = 286.74 cm²

6 0

3 years ago

Simply:12 multipled 15 (mod8)

Nataly_w [17]

Answer:

12 multiplied by 15 is 180

3 0

4 years ago

Read 2 more answers

Simplify 25^ - 1/2 <br><br>Please explain! I know the answer is 1/5 but why?

lisov135 [29]

$(25)^{-\frac{1}{2} }$