How many 3-digit numbers can be formed using the digits 1, 2, 3, 4, 5, 6, 7 if repetition of digits is not allowed?

1 answer:

7 0

Think of it this way:
_ _ _ (3 digit number)

for the first blank you could have 7 possibilities
for the second blank you could have 6 possibilities
for the third blank you could have 5 possibilities
because each time you fill in a blank one number is removed from the list of possibilities

7×6×5=210. there are 210 possibilities

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Need help quickly help me pleas

7nadin3 [17]

The mean is the average of the numbers. You add up all numbers and divide the result for how many numbers there are (14)

6+2+59+12+11+9+9+54+54+46+2+32+43+11 = 350

Mean = 350/14 = 25

6 0

3 years ago

Read 2 more answers

45 minus 4.5. Show work

Dmitrij [34]

Let's do subtraction by first starting with the ones place and then the tenths place of the subtrahend.
45-4=41; 44, 43, 42, 41
41-.5= 40.5; 40.9, 40.8, 40.7, 40.6, 40.5
45-4.5=40.5
We can check by using addition.
40.5+4.5=
44+1=
45

3 0

3 years ago

Find the axis of symmetry and the vertex and graph the following: f(x)=(x+2)(x-4)

algol [13]

something noteworthy is that the independent and squared variable in this case will be the "x", namely the graph of that quadratic is a vertical parabola.

$\bf f(x) = (x+2)(x-4)\implies 0=(x+2)(x-4)\implies x = \begin{cases} -2\\ 4 \end{cases} \\\\\\ \boxed{-2}\rule[0.35em]{7em}{0.25pt}0\rule[0.35em]{3em}{0.25pt}\stackrel{\downarrow }{1}\rule[0.35em]{10em}{0.25pt}\boxed{4}$

so the parabola has solutions at x = -2 and x = 4, and its vertex will be half-way between those two guys, namely at x = 1.

since this is a vertical parabola, its axis of symmetry, the line that splits its into twin sides, will be a vertical line, and it'll be the x-coordinate of the vertex, since the vertex hasa a coordinate of x = 1, then the axis of symmetry is the vertical line of x = 1.

8 0

3 years ago

Solve the following inequality: 10t + 7 , 200 > 21 , 000

Alla [95]

Answer:

t > 1380

Step-by-step explanation:

Subtract 7200 from both sides

10t + 7200 - 7200 > 21000 - 7200

Simplify

10t > 13800

Divide both sides by 10

10t/10 > 13800/10

Simplify

t > 1380

4 0

3 years ago

If the area of square 3 is 80 cm² and thee area of square 2 is 100 cm², what is the area of square 1?

swat32

Answer:

260 cm²

Step-by-step explanation:

Please see the attached picture for the full solution.

5 0

2 years ago