Add using a number line. -3/4 + 1 1/4
2 answers:
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Part A
Since order matters, we use the nPr permutation formula
We use n = 12 and r = 8
There are a little under 20 million different permutations.
<h3>Answer: 19,958,400</h3>Side note: your teacher may not want you to type in the commas
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Part B
In this case, order doesn't matter. We could use the nCr combination formula like so.
We have a much smaller number compared to last time because order isn't important. Consider a group of 3 people {A,B,C} and this group is identical to {C,B,A}. This idea applies to groups of any number.
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Another way we can compute the answer is to use the result from part A.
Recall that:
nCr = (nPr)/(r!)
If we know the permutation value, we simply divide by r! to get the combination value. In this case, we divide by r! = 8! = 8*7*6*5*4*3*2*1 = 40,320
So,
Not only is this shortcut fairly handy, but it's also interesting to see how the concepts of combinations and permutations connect to one another.
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<h3>Answer: 495</h3>Answer:
One year ago, he had height of 150 cm.
Step-by-step explanation:
We have to model this situation.
The first step is having everything as the same unit. I am going to work in meters initially.
Each m is 100 cm. So 10cm = 10/100 = 0.1m.
I am also going to say that his height one year ago was x.
His height is now 1.6m, which is 10cm = 0.1m above his height last year, which was x. So
His height last year was 1.5m.
In centimeters, that is 1.5*100 = 150 cm.