Both circles have the same center. The circumference of the inner circle is 25.12 millimeters.

Mathematics

1 answer:

stira [4]3 years ago

8 0

Answer:

Step-by-step explanation:

let r be radius of inner circle.

2πr=25.12

πr=25.12/2=12.56

3.14r=25.12

r=12.56/3.14=4

outer radius R=4+4=8 mm

reqd. area=πR²-πr²=π(R²-r²)=3.14(8²-4²)=3.14(64-16)=3.14×48= 150.72 mm²

You might be interested in

0.038 x 10 with a power of negative 2

Ghella [55]

The correct answer will be 0.00038

The easiest way to solve is if the exponent is positive you move the decimal to the right and if the exponent is negative the decimal moves to the left.

3 0

3 years ago

How do you find surface area? If you can explain it that would be great :) thank you!

zepelin [54]

Answer:

SA=2lw+2lh+2hw

Step-by-step explanation:

Surface area is the sum of the areas of all faces (or surfaces) on a 3D shape. We can also label the length (l), width (w), and height (h) of the prism and use the formula, SA=2lw+2lh+2hw, to find the surface area.

3 0

3 years ago

The weight of a small Starbucks coffee is a normally distributed random variable with a mean of 330 grams and a standard deviati

just olya [345]

Answer:

Weights of at least 340.1 are in the highest 20%.

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this problem, we have that:

$\mu = 330, \sigma = 12$