4 years ago

How many different 10 digit phone numbers are possible if numbers can be repeated

1 answer:

8 0

It was would numbers 000-000-0000 through 999-999-9999. So that would be 9,999,999,999 + 1 = 10 billion different 10-digit phone numbers.

You might be interested in

A fish swims upstream a distance of 16 miles in a river with a current of 3 miles per hour. The fish returns swimming

arlik [135]

Answer:

9 mph = the speed in still water

Step-by-step explanation:

Let r = the speed in still water

Then the speed going down stream is r + 3

and the speed going upstream is r - 3

d = rt or t = d/r

time going downstream is 16/(r + 3) and time going upstream is 16/(r - 3)

The total time was 4 hours, so

$\frac{16}{r + 3} + \frac{16}{r - 3} = 4$ Multiply thru the equation by (r + 3)(r - 3)

Then 16(r - 3) + 16(r + 3) = 4(r + 3)(r - 3)

16r - 48 + 16r + 48 = $4r^{2}$ - 36

$4r^{2}$ - 36 = 32r

$4r^{2}$ - 32r - 36 = 0

$4(r^{2} - 8r - 9) = 0$

4(r - 9)(r + 1) = 0

r = 9 or -1

But a rate of speed cannot be negative, so x ≠ -1

So, r = 9 mph = the speed in still water

7 0

3 years ago

In a geometric sequence, a4=7 and a6=28<br> use the geometric sequence to find a5

bearhunter [10]

I hope this helps you

5 0

4 years ago

Elaine can travel 63 meters in 3 second what is Elaine rate of speed?

vovangra [49]

Answer:

75,600 m/h (21 m/s, 0.02 km/h)

Step-by-step explanation:

6 0

3 years ago

Read 2 more answers

juan bought supplies for his new gecko. He bought four plants for p dollars each. He also bought a 10-gallon tank for $10 and a

murzikaleks [220]

Cost of 1 plant = $ p

Cost of 4 plants = $(4p)

Cost of a 10-gallon tank = $10

Cost of a water dish = $3

Total cost = 4p + 10 + 3 = 4p + 13

7 0

4 years ago

Find product of 9000and800

patriot [66]

Answer:

7200000

Step-by-step explanation:

4 0

3 years ago