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3 years ago

Two customers went to a post office to buy postcards and large envelopes. Each postcard

Mathematics

1 answer:

astraxan [27]3 years ago

4 0

The right answer is Option A.

Step-by-step explanation:

Let,

x be the postcards

y be the large envelops

According to given statement;

14x+5y=12 Eqn 1

10x+15y=24.80 Eqn 2

Multiplying Eqn 1 by 3;

$3(14x+5y=12)\\42x+15y=36\ \ \ Eqn \ 3$

Subtracting Eqn 2 from Eqn 3;

$(42x+15y)-(10x+15y)=36-24.80\\42x+15y-10x-15y=11.20\\32x=11.20\\$

Dividing both sides by 32

$\frac{32x}{32}=\frac{11.20}{32}\\x=0.35$

Putting x=0.35 in Eqn 1;

$14(0.35)+5y=12\\4.90+5y=12\\5y=12-4.90\\5y=7.10$

Dividing both sides by 5

$\frac{5y}{5}=\frac{7.10}{5}\\y=1.42$

Therefore, one large envelope costs $1.42

The right answer is Option A.

Keywords: linear equations, subtraction

Learn more about linear equations at:

#LearnwithBrainly

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Complete Question

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Answer:

The value is $P(x_1 + x_2 \ge 2 )= 0.5940$

Step-by-step explanation:

From the question we are told that

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Generally the probability distribution function for Poisson distribution is mathematically represented as

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Here x represent the number of state which is 2 i.e $x_1 \ \ and \ \ x_2$

Generally the probability that by 2030 at least two fires will have occurred at these reactors is mathematically represented as

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=> $P(x_1 + x_2 \ge 2 ) = 1 - [ P(x_1 = 0 , x_2 = 0 ) + P( x_1 = 0 , x_2 = 1 ) + P(x_1 , x_2 = 0)]$

=> $P(x_1 + x_2 \ge 2 ) = 1 - P(x_1 = 0)P(x_2 = 0 ) + P( x_1 = 0 ) P( x_2 = 1 )+ P(x_1 = 1 )P(x_2 = 0)$

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$P(x_1 + x_2 \ge 2 )= 0.5940$

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