For the first one: A=pi*r^2*1/8 (1/8 becuase we are finding the area of one pane)
A=pi*16/8
A=2pi

For the second one: First do the larger circle minus the smaller circle (pretend they are whole circles)
A(larger)=pi*18^2
=324pi

A(smaller)=pi*8^2
=64pi

A=324pi-64pi =260pi

Now, a whole circle is 360 degrees so 150 degrees is 5/12 of a circle. We take 5/12 of 260pi to get the answer

260pi*5/12=340.3

7 0

3 years ago

The book store is having a sale where all hardcover books are 20% off. Jamie also has a coupon for 15% off any fiction book. Jam

scoray [572]

You can use the fact that both 20% and 15% discounts will be merged to reduce 35% of the price of the book that Jamie buys.

By buying the book on sale and using the coupon, Jamie will save

Option B: $11.55

<h3>
How are discounts calculated for the case when its sale and we've got discount coupons too?</h3>

Suppose the sale gives p% off.

And the discount coupon provides q% off.

Then we have total discount applied on the cost of the object bought as

(p+q)%

<h3>How to find the percentage from the total value?</h3>

Suppose the value of which a thing is expressed in percentage is "a'

Suppose the percent that considered thing is of "a" is b%

Then since percent shows per 100 (since cent means 100), thus we will first divide the whole part in 100 parts and then we multiply it with b so that we collect b items per 100 items(that is exactly what b per cent means).

Thus, that thing in number is

$\dfrac{a}{100} \times b$

<h3>Using the above fact to calculate the amount that Jamie saved </h3>

Since the sale offers 20% discount and Jamie has got 15% discount coupon for any fiction book, thus, total 35% will be discounted if Jamie buys fiction book.

Since the price of the fiction book that Jamie brought is $32.99, thus,

Saved amount = 35% of $32.99 = $\dfrac{32.99}{100} \times 35 = 0.3299 \times 35 \approx \$11.55$

Thus,

By buying the book on sale and using the coupon, Jamie will save

Option B: $11.55

<h3 />

Learn more about percentage here:

brainly.com/question/11549320

5 0

2 years ago