All categories

3 years ago

10

Mathematics

1 answer:

sveta [45]3 years ago

8 0

This question was not written properly

Complete Question

Steve has 54 stamps in his collection of 13 cent, 29 cent, and 45 cent stamps, totaling a value of $15.98. If the number of 13 cent stamps is doubled, the new total value of his stamp collection would be $17.80. Find the number of each type of stamp in his collection.

Answer:

a) The number of 13 cent = 14

b) The number of 29 cent = 24

c) The number of 45 cent = 16

Step-by-step explanation:

We are told he has 54 stamps in total.

These stamps are;13 cent, 29 cent, and 45 cent stamps.

Let's

Number of 13 cent = a

Number of 29 cent = b

Number of 45 cent = c

Hence,

a + b + c = 54........... Equation 1

The total value of the 3 stamps are $15.98.

1 cent = $0.01

We have

0.13a + 0.29b + 0.45c= $15.98 ......... Equation 2

We know from the question that:

13 cent stamps is doubled, the new total value of his stamp collection would be $17.80.

Therefore

2(0.13a) + 0.29b + 0.45c = 17.8

0.26a + 0.29b + 0.45c = 17.8 ......... Equation 3

Combining Equation 2 and 3 together

0.13a + 0.29b + 0.45c= 15.98 ......... Equation 2

0.26a + 0.29b + 0.45c = 17.8 ......... Equation 3

We eliminate b and c by Subtracting Equation 3 from 3

0.13a = 1.82

a = 1.82/0.13

a = 14

a + b + c = 54........... Equation 1

Since a = 14

14 + b + c = 54

b + c = 54 - 14

b + c = 40

c = 40 - b

Substitute 40 - b for c and 14 for a is Equation 2

0.13a + 0.29b + 0.45c= 15.98 ......... Equation 2

0.13(14 ) + 0.29b + 0.45(40 - b) = 15.98

= 1.82 + 0.29b + 18 - 0.45b = 15.98

Collect like terms

1.82 + 18 - 15.98 = 0.45b - 0.29b

3.84 = 0.16b

b = 3.84/0.16

b = 24

Hence: Solving for c

a + b + c = 54........... Equation 1

14 + 24 + c = 54

38 + c = 54

c = 54 - 38

c = 16

Therefore,

The number of 13 cent = 14

The number of 29 cent = 24

The number of 45 cent = 16

You might be interested in

i need info on 3 cars, including make, model and selling price. then i need each cars depreciation rate. ill give brainliest. (p

myrzilka [38]

Answer:

1) Mercedes Benz A class which is $ 33495 (starting),

made in Germany

https://www. truecar .com/prices-new/mercedes - benz/

It has depreciation 6% in the first three years https:// www .themoneycalculator .com/vehicle-finance/calculators/car-depreciation-by-make-and-model/MERCEDES-BENZ/A_CLASS/

2) Ferrari 458 $35,563

https:// www. ferrari. com/en-EN/auto/458-speciale

Ferrari 458 models depreciate 29% in the first three years

https://www. themoneycalculator .com/vehicle-finance/calculators/car-depreciation-by-make-and-model/FERRARI/458/

3)Honda Civic $20,950

https:// automobiles .honda .com/civic

depreciation is 34%

https:// www. themoneycalculator .com /vehicle-finance/calculators/car-depreciation-by-make-and-model/HONDA/CIVIC/

3 0

3 years ago

Hep I’ll give brainliest

PilotLPTM [1.2K]

Use this to help you.

6 0

3 years ago

Read 2 more answers

The distance d traveled at a constant speed r is directly proportional to the time t spent traveling. a car moving at a constant

svet-max [94.6K]

150/2.5=x/6 is the proportion

3 0

2 years ago

Read 2 more answers

businessText message users receive or send an average of 62.7 text messages per day. How many text messages does a text message

KiRa [710]

Answer:

(a) The probability that a text message user receives or sends three messages per hour is 0.2180.

(b) The probability that a text message user receives or sends more than three messages per hour is 0.2667.

Step-by-step explanation:

Let X = number of text messages receive or send in an hour.

The random variable X follows a Poisson distribution with parameter λ.

It is provided that users receive or send 62.7 text messages in 24 hours.

Then the average number of text messages received or sent in an hour is: $\lambda=\frac{62.7}{24}= 2.6125$ .

The probability of a random variable can be computed using the formula:

$P(X=x)=\frac{e^{-\lambda}\lambda^{x}}{x!} ;\ x=0, 1, 2, 3, ...$

(a)

Compute the probability that a text message user receives or sends three messages per hour as follows:

$P(X=3)=\frac{e^{-2.6125}(2.6125)^{3}}{3!} =0.21798\approx0.2180$

Thus, the probability that a text message user receives or sends three messages per hour is 0.2180.

(b)

Compute the probability that a text message user receives or sends more than three messages per hour as follows:

P (X > 3) = 1 - P (X ≤ 3)

= 1 - P (X = 0) - P (X = 1) - P (X = 2) - P (X = 3)

$=1-\frac{e^{-2.6125}(2.6125)^{0}}{0!}-\frac{e^{-2.6125}(2.6125)^{1}}{1!}-\frac{e^{-2.6125}(2.6125)^{2}}{2!}-\frac{e^{-2.6125}(2.6125)^{3}}{3!}\\=1-0.0734-0.1916-0.2503-0.2180\\=0.2667$

Thus, the probability that a text message user receives or sends more than three messages per hour is 0.2667.

6 0

2 years ago

X+y+z=2 X-y-z=2 x-y+z=-6

likoan [24]

<h2>The first one:</h2>

solve for x.

Step 1: Add -y to both sides.

x+y+z+−y=2+−y

x+z=−y+2

Step 2: Add -z to both sides.

x+z+−z=−y+2+−z

x=−y−z+2

solve for y.

Step 1: Add -x to both sides.

x+y+z+−x=2+−x

y+z=−x+2

Step 2: Add -z to both sides.

y+z+−z=−x+2+−z

y=−x−z+2

solve for z.

Step 1: Add -x to both sides.

x+y+z+−x=2+−x

y+z=−x+2

Step 2: Add -y to both sides.

y+z+−y=−x+2+−y

z=−x−y+2

<h2>The second one:</h2>

solve for x.

Step 1: Add y to both sides.

x−y−z+y=2+y

x−z=y+2

Step 2: Add z to both sides.

x−z+z=y+2+z

x=y+z+2

solve for y.

Step 1: Add -x to both sides.

x−y−z+−x=2+−x

−y−z=−x+2

Step 2: Add z to both sides.

−y−z+z=−x+2+z

−y=−x+z+2

Step 3: Divide both sides by -1.

−y /−1 = −x+z+2 /−1

y=x−z−2

solve for z.

Step 1: Add -x to both sides.

x−y−z+−x=2+−x

−y−z=−x+2

Step 2: Add y to both sides.

−y−z+y=−x+2+y

−z=−x+y+2

Step 3: Divide both sides by -1.

−z /−1 = −x+y+2 /−1

z=x−y−2

<h2>The third one:</h2>

solve for x.

Step 1: Add y to both sides.

x−y+z+y=−6+y

x+z=y−6

Step 2: Add -z to both sides.

x+z+−z=y−6+−z

x=y−z−6

solve for y.

Step 1: Add -x to both sides.

x−y+z+−x=−6+−x

−y+z=−x−6

Step 2: Add -z to both sides.

−y+z+−z=−x−6+−z

−y=−x−z−6

Step 3: Divide both sides by -1.

−y /−1 = −x−z−6 /−1

y=x+z+6

solve for z.

Step 1: Add -x to both sides.

x−y+z+−x=−6+−x

−y+z=−x−6

Step 2: Add y to both sides.

−y+z+y=−x−6+y

z=−x+y−6

I hope this was helpful <3

3 0

3 years ago