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3 years ago

7

Find how many two digit numbers are divisible by 3

1 answer:

Bad White [126]3 years ago

7 0

I'll use arithmetic series to find it.

First two-digit number divisible by 3 is 12, last such number is 99. Every 3rd number is divisible by 3.

So,

$a_1=12\\a_n=99\\d=3\\n=?\\\\a_n=a_1+(n-1)\cdot d\\99=12+(n-1)\cdot 3\\3n-3=87\\3n=90\\n=30$

<u>There are 30 such numbers.</u>

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If 1 card is drawn at random from a standard 52-card deck, what is the probability that the card drawn is a king?

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Answer:

1/13 chance or roughly 7.7% chance.

Step-by-step explanation:

There are 4 Kings in a standard 52-card deck. If one King was to be pulled out, you'd get a probability of 4/52 chance of pulling a king. Simplified, 4/52 is 1/13 chance.

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3 years ago

Someone solve this equation much appreciated!

daser333 [38]

Answer:

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Step-by-step explanation:

this can be done by simple manipulation .
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given equation: A = 1/2 bh

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3 years ago

Find the value of B - A if the graph of Ax + By = 3 passes through the point (-7, 2), and is parallel to the graph x + 3y = -5.

Elena-2011 [213]

Answer:

$B - A = -6$

Step-by-step explanation:

Given

Point: (-7,2)

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Required

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Divide both sides by 3

$\frac{3y}{3} = -\frac{5}{3} - \frac{x}{3}$

$y = -\frac{5}{3} - \frac{x}{3}$

The slope of the line is the coefficient of x

Slope = $- \frac{1}{3}$

The question says line Ax + By = 3 is parallel to line x + 3y = -5; This means that they have the same slope of $- \frac{1}{3}$

Having calculated the slope, next is to calculate the equation of the line using the following formula;

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Substitute these values in the formula above; the formula becomes

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Cross Multiply

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Open brackets

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Add x to both sides

$x - x - 7 = 3y - 6 + x$

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Multipby both sides by -3

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