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3 years ago

How many different 2-digit numbers are there with the following property: the tenth digit is greater than the units digit?

Mathematics

1 answer:

EastWind [94]3 years ago

8 0

Answer:

There is 45 different 2-digit numbers.

Step-by-step explanation:

My way is kinda dumb, but it still works. So, 2 digit numbers is from 10-99. We can start from the 10-19 first.

10, 11,12,13,14,15,16,17,18,19

We need to find the numbers that the tenth digit is greater than the units digit.

10, 11,12,13,14,15,16,17,18,19

Since 1 is the tenth digit, all the ones digits are all going to be bigger. Same goes with 20-29. Then you will have 2 numbers that the tenth digit is greater. My way applies when the tenth digit is only less than the ones digit, not greater. If you do this way...

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

10-19: 1 number

20-29: 2 numbers

30-39: 3 numbers

40-49: 4 numbers

50-59: 5 numbers

60-69: 6 numbers

70-79: 7 numbers

80-89: 8 numbers

90-99: 9 numbers

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

So, if you add 1+2+3+4+....+9(which all of you probably memorized by now) it would be 45. The answer is 45. Hope this helped!

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Answer:

=> 216

Step-by-step explanation:

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3 years ago

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What is 3 1/2 Miles - 3520 yards converted to Miles

Papessa [141]

we are given

$3\frac{1}{2} miles-3520 yards$

Since, we have to find our value in miles

so, we need to change everything in terms of miles

and then we can combine them

so, we will have to change 3520 yards into miles

we know that

$1 mile =1760 yards$

or we can also write it as

$1760 yards=1 miles$

now, we can find for 1 yard

so, we can divide both sides by 1760

$\frac{1760}{1760} yard =\frac{1}{1760} mile$

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now, we can find for 3520 yards

so, we can multiply both sides by 3520

$3520*1yard =3520*\frac{1}{1760} mile$

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now, we can replace it in our expression

$=3\frac{1}{2} miles-2miles$

now, we can simplify it

$=(3+\frac{1}{2}) miles-2miles$

$=(3+\frac{1}{2}-2) miles$

$=(1+\frac{1}{2}) miles$

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3 years ago

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Because of Theorem 5.47 any function that is continuous on (0, 1) but unbounded cannot be uniformly continuous there. Give an ex

almond37 [142]

Answer:

$f: (0,1) \to \mathbb{R}$

$f(x) = \sin(1/x)$

Step-by-step explanation:

f is continuous because is the composition of two continuous functions:

$g(x) = \sin(x)$ (it is continuous in the real numbers)

$h(x) = 1/x$ (it is continuous in the domain (0,1))

It is bounded because $-1 \leq \sin(\theta) \leq 1$

And it is not uniformly continuous because we can take $\varepsilon = 1$ in the definition. Let $\delta > 0$ we will prove that there exist a pair $x,y\in \mathbb{R}$ such that $|x-y|< \delta$ and $|f(x) -f(y)|> \varepsilon = 1$ .