1. a music store marks up the instruments it sells by 30%. a. if the store bought a guitar for $45, what will be its store price? b. if the price tag on a trumpet says $104, how much did the store pay for it? c. if the store paid $75 for a clarinet and sold it for $100, did the store mark up the price by 30%?

A.  $58.50

B.  $80

C.  No. The markup was 33 1/3%

Step-by-step explanation:

You are expected to know the relevant relationship is ...

   cost + markup = selling price . . . . also called "store price" in this problem

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A. The markup is 30% × $45 = $13.50, so the store price is ...

  $45 + 13.50 = $58.50

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B. When the 30% markup is added to the 100% cost, the selling price is 130% of the cost, or 1.30 times the cost. Here you have ...

  $104 = 1.30 × cost

  $104/1.3 = cost = $80 . . . . . divide by the coefficient of cost

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C. The markup is $100 -75 = $25, so the markup percentage based on cost is ...

  $25/$75 × 100% = 33 1/3%

This is not 30%.

the answer is b: 18

step-by-step explanation:

use the pythagorean theorem to .

a^2+b^2=c^2

plug 18 for "r"

the 2 legs are 18 and 24

18^2+24^2=c^2

324+576=c^2

900=c^2

c=30

30-12=18

18 is the radius

: )

(b) 240

step-by-step explanation:

first, we use the pythagorean formula using the given side lengths to find x. then we use x to find the side lengths. then we add the side lengths to find the perimeter.

pythagorean theorem formula:

a^2 + b^2 = c^2

(x - 20)^2 + (x - 40)^2 = x^2

x^2 - 40x + 400 + x^2 - 80x + 1600 = x^2

x^2 -120x + 2000 = 0

(x - 100)(x - 20) = 0

x - 100 = 0 or x - 20 = 0

x = 100 or x = 20

we see that the solution x = 20 must be discarded because it will give a negative side length and a side length of 0. the only valid solution is x = 100.

perimeter = sum of the lengths of the sides

perimeter = x + x - 20 + x - 40

perimeter = 3x - 60

replace x with 100.

perimeter = 3(100) - 60

perimeter = 300 - 60

perimeter = 240