Find the exact area of the region bounded by two concentric circles with radil 10 inches and 6 Inches.

169

649

887

Area bounded by the concentric circles is 200.96 inches

Step-by-step explanation:

Step 1 :

Given

radius of the outer circle = 10 inches

So the area of this circle  = × r² =  = × 10² = 100  

radius of the inner circle  = 6 inches

So the area of this circle  = × r² =  = × 6² = 36  

Step 2 :

The area bounded by concentric circles can be found by subtracting the inner circle's area from the outer circle's area.

Hence area bounded by the concentric circles = 100   - 36   = 64   = 64 * 3.14 = 200.96 inches

Step 3 :

Answer :

Area bounded by the concentric circles is 200.96 inches

$450 is the answer.

step-by-step explanation:

30% of 450 = 135

450-135=315

step-by-step explanation: so we look at the formula un = a + (n-1)d

un is the amount of seats

n is the nth term aka row number

a is the original sequence/row number

d is the difference between each term

so in this a=22 d=6 and n can remain as n because we are simply formjng a rule

lets put these in the equation

un=22+(n-1)(6)

this is your answer to part a

however

lets double check that this is correct, we'll try putting it into the second term

un=a+(n-1)d

u2=22+(2-1)(6)

u2=22+6

u2=28

as the question said the second row has 28 seats so now we know the formula we made is correct.

as for part b

un=a+(n-1)

its asking us to find a row with 100 seats.

remember un was the amount of seata so all we do is substitute this in.

un=100 a=22 d=6

un=a+(n-1)d

100=22+(n-1)(6)

so now we simplify to find n which is the row number.

100-22=22+(n-1)(6)-22

78=(n-1)(6)

78/6=(n-1)(6)/6

13=n-1

13+1=n-1+1

14=n

so now we know that in the 14th row there is 100 seats.

hope this and that you understood! its my first time using the app or anyone out on here : p its also me to revise so a bunch! ask more questions if you dont understand ☺